232 - 2025 Wrap up episode - How fires turn into catastrophies

Catastrophes don’t happen because of one bad decision; they happen when many small assumptions fail at the same time. I take this opportunity to talk about my thoughts related to the Wang Fuk Court fire in Hong Kong. I attempt to examine how a routine ignition escalated into hundreds of compartment fires across multiple buildings—and what that says about the limits of our current fire engineering. Keep in mind these are the opinions of myself! 

We start by challenging a comforting belief: that prescriptive rules and performance-based designs can handle “the big one.” They can’t if the event steps outside the envelope. You’ll hear why compartment-focused strategies struggle when geometry and wind synchronize flames, how cavity spaces in light wells amplify heat and acceleration, and why nonlinearity means a modest increase in heat release can explode into a different regime of flame spread and radiation.

We break down the ingredients that turned risk into disaster: star-shaped towers with interior wells, bamboo scaffolding and netting near openings, temporary polystyrene window covers, and a dry monsoon pushing firebrands far beyond the origin. We also dig into response realities—why sprinklers and hydrants are sized for one or two compartments, not dozens at once—and the hydraulic and access limits firefighters face at height.

Most importantly, we translate insights into action. Learn how to make extreme scenarios explicit with safety cases during construction, align tests with actual exposure on façades and cavities, replace flammable temporary coverings with noncombustible barriers, and plan targeted, temporary suppression where geometry concentrates risk. No single fix will prevent every tragedy, but narrowing the gap between our models and real fire behavior can save lives and homes.

If this conversation helped you see fire risk differently, subscribe, share the episode with a colleague, and leave a quick review—what’s the most overlooked hazard you think we should explore next?

I would like to wish you a Happy New Year 2026! Let's hope it is a year of thriving fire safety.

Cover image: By am730 - YouTube: 大埔宏福苑五級火 蔓延7幢樓宇 至少13死28傷一消防殉職 – View/save archived versions on archive.org and archive.today(At 0:46 of the video), CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=179003054

Wikipedia article about the Wang Fuk Court fire: https://en.wikipedia.org/wiki/Wang_Fuk_Court_fire

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

Chapters

• 0:00 Year-End Reflections And Theme
• 3:20 Defining The Catastrophe Question
• 5:12 A Year Of Record Wildfires
• 7:55 Limits Of Our Safety Box
• 9:53 First Look At Wang Fu Court
• 12:40 Early Footage And Losses
• 15:15 Media Narratives And Caution
• 18:20 Can Fire Be Prevented
• 22:10 Society’s Safety Contract
• 25:10 Testing, Design Fires, And Gaps
• 29:05 When Systems Meet Unplanned Scenarios
• 31:05 Sprinklers And Hydraulic Limits
• 33:25 Nonlinearity Of Fire Growth
• 37:05 Hong Kong’s Cavity Geometry
• 41:20 Bamboo, Netting, And Fuel Dynamics
• 45:28 Wind, Firebrands, And Spread
• 48:15 Beyond The Boundaries Of Design
• 51:10 Can We Do Better

Transcript

SPEAKER_00: 0:00

Hello everybody, welcome to the Fire Science Show. It's the New Year's Eve in here, the last day of the year, which means it's a good time for reflecting back over the things that happened during the year. And the things that happened were obviously fires, and unfortunately, there was a lot of them and there were some big and horrible ones during the year. And uh given the chance and a good date for reflecting on the past, I would like to spend this episode discussing how I perceive the role of our industry in light of those disastrous fires. We started the year with uh Palisades fire, and this was already discussed in some way directly and in some ways indirectly, where we had a lot of episodes on hardening structures and response to wildfires. And at the end of the year, just a few weeks ago, we also had a fire that's gonna kind of define this year in the history books, the Hong Kong Fire in the Wang Fu court. I have not had a chance to comment on that yet, so I'll use this fire as an example in today's episode to discuss, to give you some of my perspectives on our discipline. We will talk about fire as a part of risk analysis, we'll talk about fire engineering and what we actually can do, what we cannot do. Uh we will talk about fire physics and how how sometimes our classical approach to fire dynamics is not enough and how fires scale up to monstrous sizes and what causes that. I'll at least I try to give you my impression on what causes that and I hope it's a good one. And finally we'll think about uh being able to prevent such tragedies and and being able to learn from those lessons and with hindsight think if if this could have been prevented. What could we do as fire engineers to prevent those fires? I mean lessons like like the ones we've learned this year, uh it's the best to think we can do is to learn from them. Hopefully not repeat them. It's unlikely we'll gonna change the world overnight and unlikely we'll prevent all of those catastrophes. But if we understand what turns a fire into the catastrophe, I think we will be much better off. I think that's that's the theme. That's the theme I wanted to find for this episode. What turns a fire into a catastrophe? Illustrated by the unfortunate events of year 2025. Let's spin the intro and jump into the episode. Welcome to the Fires Show. My name is Voyage Vingzhinski, and I will be your host. The Firescience Show is into its third year of continued support from its sponsor OFR Consultants, who are an independent multi-award-winning fire engineering consultancy with a reputation for delivering innovative safety-driven solutions. As the UK leading independent fire consultancy, OFR's globally established team have developed a reputation for preeminent fire engineering expertise with colleagues working across the world to help protect people, property, and the planet. Established in the UK in 2016 as a startup business by two highly experienced fire engineering consultants, the business continues to grow at a phenomenal rate with offices across the country in eight locations from Edinburgh to Bath and plans for future expansions. If you're keen to find out more or join OFR consultants during this exciting period of growth, visit their website at OFRConsultants.com. And now back to the episode. I always like this part of the year when something kind of ends, something kind of starts. I mean, if you think about it, it's episode 232. Next week there's gonna be episode 233. There's no significant value in those episode numbers, but in some way the ending year allows us to close up uh to compartmentalize the experiences gained into one uh book of 2025, put it on the shelf and read from it, learn from it, uh turning continuous time flow into discrete uh elements, kind of. And within this team I thought what to do for the last episode of the year. Last year I skipped it. That was not a bad decision to be honest, because this year has been overwhelming and uh definitely rest is something I need a lot. But to be honest, it's it's real fun and joy to record those episodes, so it does not feel like work at all. Therefore I'm happy to be here, and if there's anyone listening interested in what I have to say at the end of the year or at the beginning of the new year, you're very welcome to be on this journey with me. I told you we will talk about uh events of this year and notably the Wang Fu Court Fire in Hong Kong that happened a few weeks ago. But that was not the only thing that happened during the year. There was like this year was really, really intense in terms of fires. I think we'd see less and less of that in media because it's just boring news if you have the news about the biggest fire every week. But this year was kind of like that. This wildfire season was ridiculous. There there was, I think, one million hectares burned in the Americas. There was like one million hectares burned in the EU in wildfires. That's the biggest on on the record. That was the worst Mediterranean region year of the year. We had the biggest wildfire happening in Japan. We had the biggest wildfire happening in South Korea. Actually, uh in Japan, there was a fire in Kyushu Prefecture, Oita fire, where they had the largest in 50 years urban conflagration not caused by an earthquake. This is insane. Like we have been past the age of urban conflagrations, and here we we had a fire that burned 170 plus buildings. It really scares me because I I thought that the age of conflagrations is gone, but apparently they may be just on halt, which is a terrifying, terrifying news for fire science and fire safety engineering. And this is actually what what we need to discuss in this podcast episode. Because I think while our everyday job is to provide safety to the typical buildings that we do, you know, we we have this pathway of fire safety engineering, the goals, what we want to achieve, provide safe evacuation, provide for firefighting, compartmentalize, etc. We're quite good at doing those. And this is the product of fire safety engineering, and this is the fire safety engineering that is much, much, much needed by the society. This is something that you can see in the yearly statistics of deaths in fires. This is the reason the fire safety engineering is the reason why if you compare the last hundred years they're going down. Because of the great work that we do at the fundamentals protecting society from the general risk of fire. However, while we do that, there are some boundaries in which we do that. There are some boxes in which we work. And fires definitely do not respect those boundaries or boxes. They do not care about the great work that we have done and the boundaries that we set for ourselves, and they're happy to grow beyond that. And there are also many actors, stakeholders, which are not fully compliant with what we tell them. And yeah, they create pathways for those fires to escape our boundaries we've created for them. And there's also monetary optimization, risk considerations, societal acceptance, uh other goals, other needs, etc. etc., which make our job so, so, so much harder. But regardless, I think we're doing a great job as uh as fire safety engineers. And now we go into the Hong Kong uh Wang Fu Court Fire. I learned about the fire from a chat with fellow firefighters. There was a lot of noise in my uh WhatsApp seeing firefighters discuss this ongoing event. There was a live stream of the fire at some point, and I remember sitting down on my computer working on a project, and on another screen I had the live stream of the one who caught fire. Like looking at that, it was insane. There was like multiple buildings on fires, and you could see it's a collection of multiple compartment fires. Like you could see on the pictures on the videos that it was not like a single continuous facade fire or something. No, it was a collection of compartment fires. You could like distinguish them. I've counted, I think, like 30 something on the video feed that I was watching at the point where I was watching it. Horrible tragedy. Like so many compartment fires. It means that this is very, very bad, and it was immediately obvious this is uh probably the worst fire of a year. At that point, there was no real knowledge about how the fire started. However, later uh someone uploaded videos of the very early stage of the fire, which are quite interesting to see because you can see the fire growing from a very little fire in uh in the bottom of the building to a really, really massive fire in the in the building cavity, and it's uh within the span of one TikTok video, which is ridiculous. And at that point we also had no idea how bad the losses uh will be. The the news uh came later, uh after a few days we've learned that there was 161 fatalities, including one firefighter. This is ridiculous. So many lives lost in in a single fire. But beside that, there was eight buildings. Eight buildings with thousands of uh units. Uh from what I've learned, there was like nearly 2,000 houses in that complex. And they're all lost. 2,000 houses lost. So many people that have lost their household. Well they are happy probably they survived it, but still this is something that will influence their lives for many, many years. Horrible tragedy. And uh immediately after, like immediately after the fire happened, there was this massive media attention given to the fire. I've seen colleagues giving uh interviews everywhere, BBC, CNBC, whatever international televisions you have. There seems to be an immediate interest of the society in fires after a tragedy like this. I mean, I don't blame my colleagues, it's it's good that we try to uh answer the society. We're here to do that actually, and uh we need to provide them with some information, some context on what happened. It's just you know, in tragedies like this, it's not a single cause, it's not a single issue, it's not a single problem that resulted in this tragedy. And uh actually to understand the complex interactions between all the actors, that's that's a hell of a job, and that that's probably gonna follow. Immediately after the fire, like the first culprit was the bamboo, it was the bamboo uh scaffolding. Then it was no, there there was a net on the scaffolding. There were expanded polystyrene bolts covering the windows, like the firefighter response was in in inadequate. There was a strong wind, there were firebands, why the sprinklers did not contain the fire, were the alarms turned off, like a lot of a lot of things that were said about the fire in the media shortly after it. I I'm I'm unsure how to feel about this. I I have not commented on that at all in in the social media. While it's it's an opportunity to get some attention and and catch on the the theme and and answer to the interests of many people, obviously, when when you comment on a on a recent tragedy like that. I don't see the great value of you know participating in this media mix of opinions. It's because it's not the most popular or most or strongest-worded opinion. That's the most important. We need to figure out the complexity of stuff that happened. Therefore I took a step back to reflect, and here I am a month later discussing uh this fire with you. And to discuss this, uh let's let's ask some questions. And the first one I would like to ask is uh is fire preventable? And I'm not talking about this particular I'm I'm talking about fire as a concept, as a phenomenon in general. Is there a possibility we get rid of a fire? If there's no fire, there's no fire problem, right? So can we get rid of fire? And the obvious answer is no. It's impossible to get rid of a fire. It's such a complex uh phenomenon, so many pathways that lead to a fire, that uh actually we embrace this way of thinking as fire safety engineers. We often consider the probability of fire, but while doing our fire safety design for buildings where when we perform our fire engineering, we just assume the probability of fire is one. It is going to happen. And uh given the amount of buildings that we have, given the amount of you know ongoing operations over the uh over the world, even if a fire is a very unlikely low probability event, it will happen somewhere. And that means there's no simple answer of yeah, we could get rid of a fire. If you think about batteries, batteries is a very interesting case because the probability of a fire inside a battery is is ridiculously low. Like I'm not sure the number, but I think it was like 10 to minus 9. If battery experts correct me, if I'm rock, apologies for butchering your field of knowledge, but it is it's very, very low. But yet, with trillions and trillions of batteries around the world, that probability means there will be a lot of fires daily all over the world. We would have to like improve this by a factor of a thousand to actually expect there will be no fire over a year from a battery source. That that's the levels at which we are getting rid of a fire. And that's only part of the equation because we're talking here about the uh fires that originate in the battery, but uh battery can be a victim of abuse and other stuff that that actually triggers fire, and probably it's very difficult to prevent that. So while in some cases it would be like if we could get rid of it, that would be the easy solution, right? But unfortunately, there is no uh there is no button to turn off fire. We we had one, the halons, the gas uh that uh take the hydrogen radicals out of the flame chemistry, basically preventing the chemical pathways for energy generation and miraculously turning fire off. That that's a great one. Unfortunately, they're also really good at destroying the ozone layer in the atmosphere, which we kind of need, so uh we are not allowed to use it after the Montreal protocol. Uh but yeah, there's no way we can get rid of fire, and the probability of fire we need to assume is one. So now we enter this world where we are aware a fire will happen. There will be fire. What how do we prevent against it? And what actually we prevent for? And I think there is some sort of societal consensus of how fire protection should look like. It's defined in many legislation systems in many countries in very similar ways, like you should provide safe evacuation, you should provide for firefighting, you should limit the fire spread, you should compartmentalize, you should provide technical systems in your buildings, etc. etc. To achieve this fire safety, we set up a framework, legislative framework, we tell what the buildings should have, what they should be built of, how should they should be made, what should be installed in them. And society accepts that they have to spend money to install those things to keep those buildings fire safe. Now, if you think about fires like the Palisades or the Wang Fu Court fire, what happened there? It like it's difficult to consider this as a single fire. It's easy for me to consider a single fire compartment as like an individual cell in which a fire event happens. And this is my classical approach as a fire safety engineer. That's what I have been taught, that there's one fire in my building and I have to provide for that one single fire in my building. Now, if you have a fire that spreads into so many compartments or so many buildings, it kind of escapes this level at which the fire safety engineering can interact with it. Perhaps from the society point of view, we should be acting on that level. But from the fire safety engineering, this is the first box we put on ourselves, the first bound we've put on ourselves that the fire should not be present in more than one fire compartment at a time. And in that case, like what else? Well, we'll come back to that in in a second. But I I wanted to put it further. Like when we put ourselves in this box of fire safety engineering in those legislative systems, the fire does not spread, the the walls provide you fire resistance of whatever minutes. It's not just this clause of the law that defines what we need to do. The way how we provide for this is either through fire safety engineering, performance-based engineering, or through prescriptive engineering, clauses of codes, classes, etc. And for those we need testing systems set up, and those testing systems allow us to give the classes to products. And those testing systems, they are built to kind of mimic some kind of worst or possible fires that could happen and expose those elements to those hazards to show if they can respond to them correctly or not. And uh in in performance-based design, we we go with design fires, we go with plausible fire scenarios, etc. We also set up, you know, kind of an expectation on what the fire would be that we wish to react to. In both cases, these conditions are as much the part of the system as the requirement to limit the fire spread is. Because in reality, you say you the fire should not spread between the buildings. In practice, what you say is that this particular building product under irradiation of 50 kilowatts per square meter achieves this kind of performance. Or you say that assuming a design fire of 30 megawatts, the radiation in 15 meter proximity is lower than needed to ignite an element that is present there. A massive simplification. If in reality the fire gives you higher radiation than the one you had in a concolorimeter, what's gonna happen? It's gonna be different. If there's an intermediate object between the buildings that allows the fire to hop, and suddenly we're not talking about self-ignition, but we have a pilot ignition scenario, oh snap. It's not as planned. So while the regulatory system we have fundamentally should prevent us from those catastrophes, because if you think about it, look at the Wanka food court fire. The fire should not spread through the building. If this word magically meant that the fire cannot spread through the building, there we would not have uh a few hundred compartments on fire, and probably the the damage would be much less severe. In reality, even if we do our job the best, if we do the whole fire safety engineering as we are supposed to do, the regulatory system only gets us that far. And what's even worse, due to the massive complexity of the system, we sometimes, even unwillingly, take you know, some specific fire scenario. And assess hazards that are completely unrelated. Like the best one I can I can think about immediately is the SBI testing method and the facades. We use SBI to assess the flammability of materials, and then we put those materials on facades. SBI is kind of like simplified room corner, and room corner is a test to assess whether the materials contribute to flashover in compartment, which is not a facade scenario. So the regulatory system in which we practice bias safety engineering puts us in a box and in a way when a fire happens that does not respect this box, it it kind of turns into a catastrophe. And it's really sad because given all the you know uh potential uh criminal issues happened in one Kfuq court fire, because I know there will all there were already arrests, there is like uh some allegations of of the netting not meeting the fire performance, etc. Even if we assume that everything was correct and such a scenario happened, there was an external fire spread, and the systems we've designed were designed to protect us from a single fire inside the compartment, and suddenly you have multiple fires in the same buildings, we would still have a catastrophic failure of the safety system. So that's that's a that's a sad thought that a a well-engineered, successful from the perspective of fire safety engineering system can actually be exposed to a scenario where there's a catastrophe and they they stop working. Another example, think about sprinklers. Uh, the sprinklers were present in that building. I've actually had the privilege to visit Hong Kong in November. You you heard about it in the podcast. I was super excited to be there on a battery conference, but uh this visit was much more than just a battery conference. I've met with a lot of friends from Hong Kong Polytechnic University. Um my student Waiki Chung took me to the Fire Academy in Hong Kong. We had a private tour of the fire academy, we had to talk with uh with the people uh in that academy and asked the question how they they deal with the high-rise building fires, because it's obvious high-rise building fires are difficult for firefighters. They told me they rely strongly on sprinklers. And sprinkler is something that works if you have one compartment of fire, maybe two, well, it's already beyond the standardized uh use of sprinklers, but if you have multiple compartments on fire, this the water will not reach the top floors. It's it's impossible from the hydraulic perspective. And if you wanted to design a system that could at the same time provide water for all the compartments in the building, that building would be just one massive pipeline. The cost for society would be absolutely unacceptable. Therefore, yeah, the fire safety engineering is done with some constraints. And beyond those constraints, it's not gonna work. And I think the moment fire turns into a catastrophe is when the physics of the phenomena make the fire outgrow those constraints. And unfortunately there's a like a domino effect, like a nuclear reaction, chain reaction effect, with every element failing, adding to the fire and creating more of these uh elements to be outside of the compartment. I I hope you follow me. It's kind of convoluted, but but indeed, while most of our engineering provides a safety and allows those scenarios to not spiral into those uh chain reactions, sometimes the fires breach those. And those are the worst fires that we end up seeing in the front pages of media. So now let's discuss some fire physics because I think it's an important thing to consider with this uh horrible fire in Hong Kong. There's a saying that sufficiently advanced technology is indistinguishable from magic, and uh I would say uh following that trend I would say that sufficiently complex phenomenon is uh indistinguishable from a divine power, and perhaps the complexity of fire and the difficulty in understanding what actually is happening within the fire is a reason why it was given almost a divine attention in our past as a humankind. And in indeed uh I'm doing this for what twenty years? And every few weeks I see a fire that surprises me. It's ridiculous how complicated fires are and how much different physics, like rich juicy physics is there to still be discovered. And and unfortunately in the Wang Fu court fire we we had a really complex fire happening. Uh I'll try to give you in in in chunks what I think about it. Keep in mind these are my own thoughts. This is not like an inquiry. It's just a guy having a podcast just speaking his mind. I did some fires in the past and I've modeled a few of them, but it's it's just me, so don't quote me in like governmental reports or something on that. But yeah, let's try to do the physics of this fire. One, the fires are extremely nonlinear, and I mean the perception of fires is like very hard because I I think as a humans we like to perceive things that change like linearly. You would think you have a 500 kilowatt fire, you have a one megawatt fire, you have two megawatt fire. Like the first one would be like something, the second would be twice as big, the third would be four times as big, right? But it it's really not like that in the realm of fire. The growth of the fire is extremely nonlinear, and what's even worse is that the heat transfer phenomena, they each come with a different power low attached to them. So often when you have a fire change from two megawatts to four megawatts, it's not just it's twice bigger, it's like a completely different disaster. And you can also see that actually very, very well in that video of uh Wang Fuck court fire when it's growing, how it changes, how how big it becomes, how how quickly it escalates into really massive fire. And I've seen that countless times in my laboratory. Like you have a fire, it's as expected, and it grows, then it grows, and it's kind of bigger, and oh shit, it's huge. Like it really gets you by surprise how quickly this changes and how quickly the perception of that fire is. And and I don't think we appreciate this as people working with fire. Perhaps one thing is that we are not really exposed to those fires that much. Like, how many of you have seen a 10 megawatt fire? How many have seen a 30, 100 megawatt fire? It's it's like a completely different animal. And and even us, the trained and skilled fire safety engineers, it's just a few of us who have seen such an event in their life. I have an experience of doing the first OG Obora traveling fire experiment with Imperial in Poland. And even though we had like a bunch of really, really good, really experienced fire scientists in the room, I think a lot of us were surprised about the final outcome when the fire reached its full potential. How huge that was and how quickly it was spreading at some point. It's ridiculous. I had an experiment with large 70 square meter CLT buildings with CLT slabs. Got the flashover in that building. That was like probably the most intense thing I've seen in my life. Like seriously, sometimes those fires catch you. Like you would not expect how quickly the severity changes within your nonlinearity, non-linearity of the heat transfer phenomena out there. And this is not just the perception of the human, it's also, you know, the heat fluxes that ignite stuff. The fact that the fire grows and starts to emit more radiation, and this radiation can ignite, self-ignite more material that feed to that fire, and it grows even larger. That's the doom spiral, that's the chain reaction which causes those fires to grow to enormous sizes. And for us fire engineers, this is not just a perception thing, how we feel about fires that we see. No, we design fires, we use design fire concepts, we use methods that mimic some fire phenomena, and we say, yes, this is fine for the building. No, this is not fine for the building. If we misunderstand how much difference a larger fire means for the building, the safety system that we design for the building will have shortcomings. So it's it's not just a thing for you know thinking about fires or feeling the fires or being overwhelmed with the fire. No, it's it's a part of our job. And I I think this nonlinearity, we don't really intuitively understand it well. And sometimes those fires act differently than we expect them to be. This is true for compartment fires. This is true for outdoor fires that I've seen. But that that I would say are still perhaps even easier. If you look at the the buildings in Hong Kong, they have this very specific type of architecture where those buildings would have like those internal cavities, wells, I'm not even sure how to name them, you know. If you look at the cross section of the building, you'll understand. It's not like four walls, it's more like a star-shaped with a lot of internal wells inside of the building that separate the flats from each other. And they are quite massive and there are openings to them that lead to the compartments. It's a style of architecture they have in there. When I was in Hong Kong, I took a lot of pictures of those wells and a lot of videos of those wells. I would I wouldn't I remember I was sitting on the bus uh with my uh student Jakub with Vinigupta and we were looking at those buildings and we were like, oh my god, like how is this even possible or a load? Because it's obviously such a dangerous fire design. And that was before the fire, and it just happened to that part of the building was the one where where the fire started. It's obviously dangerous because you create a confined chimney in which the fire can reach very high velocities. It's very efficient at transporting air, but also it's super efficient in terms of re-radiating heat inside. So yeah, that that's kind of the architecture in which the fire is capable of reaching the largest potential. And to add to that, one thing that I've learned when dealing with cavity fires, we were uh doing those experiments with uh cavities. Uh we have built a rig where you can set whatever size of cavity you want and you can test the same uh fires. What was really shocking in those experiments was that we have achieved really massive fire outcomes, like really bad fires, flames shooting out of the facade, etc., at reasonably low heat release rates, like 100 kilowatts. For a 5 centimeter facade cavity and four square meters of the facade, 100 kilowatts, that's it. And we had fires shooting out of the top of the facade, I had a thousand degrees inside the cavity, etc. A fire of a trash bin, like 100 kilowatts is nothing as a design fire source. Yet, when contained in a cavity, when flattened out into like a two-dimensional shape, that is already a massive fire. And the same thing for those uh well things in the buildings. Even if they're like 20, 30 square meters in cross section, if you have few megawatts in that, that will be completely different, few megawatts than outside. I'm not saying the heat generation will be different, but the way how the heat transfer happens in that confined volume, this is gonna be as if you had much, much larger fire outside. This this is what creates the severity of those confined fires. This is what makes them dangerous. This was actually the King's Cross fire in London when we where the trench effect was discovered. Very similar phenomenon where a confined fire led uh by gravitational flow upwards chimney effect can create tremendous, tremendous uh fire damage in in the building. And uh another thing is the fuel that was present there. So uh in the early days after the um after the fire, the bamboo was the culprit. And that's a challenging thing to discuss. Like, was the bamboo the culprit or not? Because it obviously is flammable. You cannot deny that bamboo is flammable, it's it just is. But uh at the same time, is is it really a hazardous material in for scaffoldings? I'm I'm not sure. I mean, a scaffolding is a lattice system, like those bamboo sticks are really far away from each other, and if you just burn them outdoors without this cavity, without this well, I don't think you would have a strongly spreading fire. It's perhaps something that and I'm sure people will do a lot of experiments with bamboo scaffoldings right now. But I don't think in a on a flat wall you would get the same thing because of the separation. That the sticks are separated uh largely enough from each other that uh this kind of prevents the self-sustaining like fire of those sticks. If you add the flammable netting to that, huh, that's probably a different thing. But still the net, if you see the videos, it melted away, disappeared. It's not a huge mass of material. In general, the bamboo scaffolding and the netting is not a huge mass of fuel, it's not a huge fuel load. So in theory, you should not have a self-sustaining giant massive fire because how those things are separated in space. And you know, looking at the Wang Fu Courtfire and uh the classical approach that that's in my head, that I think this separation thing is a key thing to consider in here. Because we we like to consider separation as uh a function of distance, as a function of physical distance between the objects. If they are separated for sufficient distance, it's not possible that one interacts with another and they do not create a continuous flame. But I I think we also should consider this not only in the domain of space, but also like in kind of time domain. If you have those fires in cavities, they reach very large flow velocities in there, like 10 meters per second, easy. Now, when you have a fire burning, it takes some space above the fuel because of the chemical reactions that happen. They take some time to fully consume the fuel as it goes. There are hundreds, if not thousands, of chemical reactions that are concurrently occurring in the flame, and that's why the flame has a volume. That reactions have to react over, you know, that the time is needed for them to go through. The larger the fire, the more the fuel emitted, the longer it takes to mix with the oxygen from the air, the longer it takes for those uh reactions to happen. And now if you have a very high velocity, those reactions still happen, perhaps at larger speeds because uh the mixing is is promoted, but they still take some time. But now, at very high velocity, if the reaction takes a given time, perhaps it's enough time for that flame to reach the second stick of the bamboo lattice. And if it does, suddenly that stick starts to emit fuel, and the reactions continue, and then it reaches the third stick, and now you have the combined fuel from three sticks, reaching the fourth one, and the fifth and the tenth, and suddenly you have a continuous flame across 31 floors of a building, and it's in the cavity. It's in the perfect conditions to re-radiate to other sticks to ignite more fuel, to emit more fuel, and you you don't even need to have hundreds of megawatts in that cavity to create a massive consequence of fire. So even if in an outdoor lattice system the separation distance would be large enough for the buoyancy controlled flames, when you have a system in the chimney where those are accelerated, the separation distances that would prevent would be completely different. And I think that that's a huge contributor to to the tragedy. Another thing is the fire spread because you know I I think we we we consider this fire as one fire, but in fact there was hundreds of fires happening concurrently, and we need to understand the mechanism how those fires spread. One thing is the polystyrene covers on the windows. I think that that's a contributor, the wooden entrances to the building which replaced some windows where the workers could enter the scaffoldings, that's probably a contributor. But also the wind and firebrands. The the fire happened at uh a very strong wind. There was a very strong, dry monsoon wind in Hong Kong that day, and there obviously was a lot of firebrands. There were ignitions found many uh hundreds of meters from the building, from the firebrands. So I I my guess would be that the firebrands were able to carry the fire from the initial site to the other buildings in the in the Kurt. And just the same scenario repeated, you know, the the cavity fire with the fuel inside the cavity that overwhelmed the safety features of the building that cascaded outside of the scope of the fire systems that were in those buildings that were meant to provide safety. I think this is the core of what we would need to study as fire safety engineers. How this single event, single fire, what mechanisms lead to cascading that fire to actually overwhelm the boundaries of the safety systems that we have in place. And this I think this is true for all the massive fires that happened this year. The Palisades, the Fire in Japan, the Hong Kong fire. In all of them, the fire spiraled out of the boundaries that we can work and provide safety with. Not to mention that perhaps the safety was compromised by some actions or illegal activities or wrong decisions. That's out of the question. But even if there was some level of safety we could provide, and and we obviously did not because the fire spiraled out of that. So a question arises. Can we do better? How can we prevent such tragedies in the future? And God, if I only had an answer to that one, that would be awesome, but I obviously don't. I can just give some thoughts on where we should move from here. If we have a safety system set in place, playing with that safety system, you know, changing the standard requirements, etc., it technically is possible, but it would take ages to change all the testing methods to account for the new normal, a larger fire that we could expect, and even if we did that, there would still be a fire that could overwhelm the system and still lead to a tragedy. So I'm not sure if uh changing the system is the answer. I mean the system works, it's just this component where we are beyond the the where word what the system is supposed to provide is is where those catastrophic failures are. Perhaps we can add something to the systems. Perhaps we should be more explicit in testing for those extreme cases, in understanding the failures of the The systems, how fires violate those systems, how they go across the boundaries of the safety systems we provide, and what's the consequence of that, you know? Kind of like the worst case scenario analysis, perhaps risk-based, perhaps more guided like chemical processing it does for the significant events in the industrial sites. More safety cases. But it would have to be explicit, you know. We would have to have an explicit goal set in our legislation systems that we need to check for the blind spots of the safety systems that we have. We have to define the scenarios at which the systems will stop providing sufficient level of safety, how they can end up in this place and is such an event possible in a building that is being designed. I think if we were more explicit about this particular actions, we would be able to capture those events, those fires that would lead to such a catastrophic failure. And obviously for each building they could be different. Because I would assume that if the building was just a rectangle, not a star-shaped pattern, we didn't have these internal wells, it probably would not be such a massive fire. It could have been a very large fire with the firebrands, strong winds, etc. But but perhaps not a catastrophe like we've seen. And it's probably true for most of the catastrophical fires of the recent years. The extent of the tragedy would be much less severe if some of the systems were not overwhelmed and some of the systems provided the level of safety they were expected. Also, you know, we would need to think about if we have a compartment fire and it transitions into this massive, massive fire, what can we do in the meantime? If you look at the videos, uh how this fire grew to the massive size, there's not much you could do. Like it happened in two minutes. I don't think there's any sort of fire response possible. Maybe one day drones or some sort of aerial units that can deploy water at very high heights, it's extremely difficult for firefighters to reach off that those heights. Thanks to gravity, thanks to hydraulics, thanks to the pumping systems, it's just a really huge technical issue to deliver water at the thirty first floor from the outside. And that I would be far away from blaming firefighters. They probably did whatever they could to stop the fire. They were overwhelmed with the fire just as the building systems were. Could we have better response systems? I don't know, outdoor sprinklers, perhaps, but uh if you build as a case on how often we would like if you apply risk and cost-based analysis to this, it's gonna be difficult to implement anything outdoors. Perhaps the temporary systems for construction works that that could work to some extent. Still not sure if it could stop the fire in the cavity. One thing that I would immediately think of that would have helped is using non-combustible kind of fire rated partitions to windows instead of polystyrene covers. If those were like mineral wool covers with 30 minutes fire rating or something, then the fires would not be able to spread into those uh into those compartments. Probably we could keep the fire outside of the compartment in that well long enough that it doesn't spread into the compartments. And while the damage outdoors, the fire spread from the firebrands, etc., would still be there, the consequences could probably be less severe. And this is, I think, a simple fix to this uh faulty system because if you have the goal for those uh covers of the windows was to limit the noise, limit the you know exposure of the inhabitants to the construction works. So if you use uh mineral wool or other non-combustible insulative material, which is perfect for uh noise reduction as well, it's you you would achieve the same outcome in terms of performance and you would apply a layer of fire safety compartmentation that was obviously missing uh in that fire. I'm not saying it would solve the whole issue of the fire, but uh perhaps the severity would be different. I would I would do that. Though it adds costs if if there are reports that the netting was supposed to be fire retarded and was not uh because of the small change of the cost. I'm not sure if uh this is universally feasible because there will always be an actor who would like to earn some money by replacing those with a cheaper solution, but I think it's a good shot. Don't we really have more ideas of how we could prevent this? There's really little we can do in such a fierce uh fire growth. I think we if we understand the fire physics better and we understand the this nonlinearity of fire, perhaps you know, triggering warning. The fire has been they in Hong Kong they have this uh I think five-step uh level of fires and this fire advanced to the highest fifth level after a few hours, but perhaps if it was advanced in the first minutes the response would be stronger. But that would require you to fully comprehend the expected outcomes of the fire when it's still small. It's something very difficult to do. I don't think uh firefighters would be or should be expected to be able to tell oh yeah this fire can grow to a monstrous size and this cannot, when I think me as a fire scientist dealing with those I could not do. Anyway, this I think this would be it for the commentary on the Hong Kong fire and in general. The failures and and uh shortcomings of fire engineering that this fire exposed to a sad uh ending for 2025, but perhaps some lessons for the future in this. I hope you've enjoyed this to some extent, and perhaps I gave you some ideas to think about the even further. If you agree with me, tell me. If you disagree with me, please tell me. I'm really happy to engage in some conversations and I'm looking forward to see what the inquiries and the research work that is definitely started after the fire brings us and what knowledge we will we will get. There is not not a single culprit in here, there is not a single actor that whose fault this fire is. That's my belief, honest belief, that it's not a failure of a single component, it's a coincidence, failure of multiple things at the same time in a very specific external conditions that led to catastrophical spiraling of the fire into size, which overwhelmed the safety features of the buildings because they were simply not meant to be providing safety at uh a hazard of this scale. Anyway, let's give some positives in the end of the episode. Thank you for the year 2025. It was it has been an amazing year for me, like professionally, uh probably most intense year I have ever had in my life. Uh scientifically, a lot of good papers published out, a lot of projects uh moved forward, great work on visibility in smoke. I'm so proud of uh Waiki Chung and the work that we are doing on visibility in smoke. And this is finally moving forward, and next year will be the year where we can provide you with some actionable advice on how to change the status quo, the paradigm of the visibility in smoke, and I am most excited about that. It was a year where I had more personal recognition and awards that I could dream of. I was given the European Fire Safety Award by SFP Europe. Thank you so much, guys, for that. This is wow. Uh uh being able to receive this award in Edinburgh together with uh Douglas Dreisel, who received the Lifetime Award. That was something. That was something I've I've not expected that, and that that was something really. Being awarded the Lund Award from the SFP, amazing effort. Thank you so much. Like it it recognizes the contributions I may have to fire safety engineering as a profession. And if I am able to change the fire safety engineering as a profession, wow, thank you so much for telling me that and putting me in this position, and I will do my best to change the fire safety engineering profession to better, like I try with uh this particular podcast episode. In the year I was also elected as the new chair for SFP Europe. The job starts tomorrow. I better get ready. I there's a big shoes to fill after after uh Robert McNamy and his amazing two years of being the chair. If I am half as good as Robert, it's gonna be awesome. I'll try to be as uh as good as Robert was, but not sure if that is possible. He set the bar ridiculously high, and I I hope to have his support in the years of uh of uh me being the chair. I will do my best for the organization and I will uh hope that we reach some great things in Europe. We this year we also had uh published the GRC report on state of fire protection engineering, and SFP was a huge part of that report, and I'm thankful to GRC and especially Francesca Sciareta for uh allowing us to participate in this work. Locally, the Polish chapter has had an amazing year, and uh we had a bunch of events. We had one particular event about the contributions of fire safety engineering to firefighting and how the firefighter safety and ability to carry out firefighting operations should be a part of fire safety engineering. And wow, this was an amazing event and an eye-opening thing. And finally, we had a room full of fire engineers and firefighters talking about the same thing and sharing experiences. This was amazing, and I hope we can repeat that on a grander scale and a global scale in uh in next year. Uh we've closed a lot of tunneling projects in Poland. We are involved in perhaps the largest infrastructural project in Poland, which is a hell that that's why I've disappeared from social media for the last three months. I so much work. But yeah, it's it's good to have work. And um I'm in the final stages of filing my paperwork for full professorship, so maybe next year will be the year where I advance uh my professional career as well. So yeah, definitely an intense, a good year. I hope that the next year 2026 is also an awesome year. I don't expect recognition, I don't expect awards, these things happen to me, and I'm really thankful for them, but it's not those are not my goals. My goal is to deliver a lot of good content to you. 52 good podcast episodes, that would be an amazing goal for 2026. If I can have 52 occasions to share fire science and fire safety engineering with you and perhaps help someone out there, that would be awesome. I really hope I'll be able to design some safety systems for some buildings and uh provide safety to their users. I am I really hope I can become better fire safety engineers. When I said that we we don't really appreciate the non-li-n linearity of fires when we and when I say that you know our choices have consequences if we misunderstand the fire or or choose wrongly, this affects the fire safety engineering. I was talking about myself, you know. I do those mistakes, I I learn, I try to appreciate it. It's hard, it's so hard. But I tried I strive to be a better fire safety engineer, and I hope in the next year I can become a better fire safety engineer in what I'm doing. And well, I thought I think that's it. That's a long episode for a New Year's Eve. Uh, thank you for being here with me in the fire science show today for 2025. We start with some good episodes already recorded, so uh next week, next Wednesday, first episode of 2026, be there with me. See you there. Cheers. Bye. Happy New Year.