# Did Larry Silverstein know about 9/11? **URL:** \ **Category:** Great Debates\ **Created:** [July 5, 2015, 8:17pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340 "2015-07-05T20:17:23Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [July 6, 2015, 1:34pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/101 "2015-07-06T13:34:28Z")
[QUOTE=bombthefeds] First of all, even the NIST states that debris from tower 1 wasn’t the cause of the collapse and that collapse was due to fire fueled by “office combustibles” [/QUOTE] It wasn’t the cause. But it weakened the structure as part of a whole. You seem to be attempting (badly) to take each event in isolation as if it wouldn’t affect anything else and then say ‘well, this piece wouldn’t have caused the collapse’. Instead, you need to look at the bigger picture. You keep citing the NIST report, but did you actually READ the thing? I have…several times (granted, it’s been years at this point). So have several others in this thread. Reading it you’d see that it was one thing piled on top of another that was the most likely cause. Building debris from the collapse of tower 1 caused structural damage AND set fires throughout the building rapidly (which is not a normal fire vector, where in most burning buildings you have a single vector of fire). The fire suppression system that SHOULD have helped out containing or at least mitigating the fire was completely shut down due to the collapse of tower 1 and 2 and their effect on water mains in the area. Firefighters (the second line of defense) were already heavily committed and by the time they could deal with building 7 the building was beyond saving and eventually just left to burn (for many HOURS). And the design and materials of WTC 7 made it particularly vulnerable to this sort of combination of events and caused a catastrophic collapse. There is nothing mysterious in any of this, and if you had actually read the full NIST report on WTC 7 instead of parsing it for CT fantasy and bullet points you’d have seen this. Failing that, we’ve had this stupid, silly discussion about a thousand times on this message board already (which is why no one is bothering to really engage you…we are simply tired of this stupid fucking subject at this point, and the nutty CTers that bring it up and usually slink off after being slammed), so you could do a search and look over those threads and get all of this. ---
**Author:** ![The\_Stainless\_Steel\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_stainless_steel_rat/32/5727_2.png) [@The\_Stainless\_Steel\_Rat](https://boards.straightdope.com/u/The_Stainless_Steel_Rat)\ **Post date:** [July 6, 2015, 2:02pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/102 "2015-07-06T14:02:04Z")
Just for reference, here is a destruction from Germany of a rather large building (albeit not as large as Building Seven. Notice something, bombthefeds? Like the big explosions that are clearly heard blocks away? Or did Siverstein's sneaky Illuminati allies use some super-secret Hush-a-Boom explosive (with that special addition of unobtainium, of course)? Because I don't think you can find a single reference for anyone hearing such explosions. And here is another tape showing the _extensive_ preparations that go into getting ready for a controlled demolition. [Preparing a Building for Implosion - YouTube](https://www.youtube.com/watch?v=7teIVoltRjo) Fire + damage from the WTC 1& 2 collapse + gravity = Perfectly reasonable explanations. ---
**Author:** ![scabpicker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scabpicker/32/8268_2.png) [@scabpicker](https://boards.straightdope.com/u/scabpicker)\ **Post date:** [July 6, 2015, 2:06pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/103 "2015-07-06T14:06:54Z")
Seriously? Who cares, it completely lacks evidence or motive. The fire would have made the building a write-off whether it came down or not, and any incriminating contents would have been burned away. The worst thing about this CT is that it has no reason to exist. ---
**Author:** ![Willcross](https://avatars.discourse-cdn.com/v4/letter/w/b2d939/32.png) [@Willcross](https://boards.straightdope.com/u/Willcross)\ **Post date:** [July 6, 2015, 2:11pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/104 "2015-07-06T14:11:41Z")
Isn’t it possible that Larry is innocent AND the WTC 7 was demolished with explosives? I suspect the bad illuminati gave Larry a warning of the incoming (real) terror attack and told him to stay home that day. Larry, thinking the call was from the good illuminati, heeded the warning and avoided death. Then the bad illuminati, purposely destroyed Larry’s building. They knew that Larry’s missing his normal meeting on top of WTC 1, combined with the destruction and subsequent insurance claim on WTC7 would be enough to cast suspicion on Larry and away from them. Basically Larry was a patsy like Oswald was for the “Chaotic Good Illuminati”. ---
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [July 6, 2015, 2:17pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/105 "2015-07-06T14:17:38Z")
> [@Willcross](#): > > Isn’t it possible that Larry is innocent AND the WTC 7 was demolished with explosives? Sure, but there’s no reason to believe this, considering the plentiful evidence of the accuracy of the ‘official story’. ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [July 6, 2015, 2:37pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/106 "2015-07-06T14:37:04Z")
> [@scabpicker](#): > > The worst thing about this CT is that it has no reason to exist. This is what annoys me about most 9/11 CTs, to be honest - they’re ridiculously convoluted for no good reason. If you were the Government/Illuminati/Elders of Zion/Alien Overlords and you wanted people to think that a small cadre of suicidal terrorists hijacked a couple of planes and flew them into the WTC, Pentagon and potentially the White House, would you: 1. Set up a series of explosives throughout the buildings in a way that nobody who worked in any of the buildings involved would notice in advance, then hijack the planes but make them and all their passengers mysteriously disappear while using missiles with holographic projectors to simulate the effects of planes flying into the buildings, then detonate the explosives in a way that will neither look nor sound like a normal building demolition, a plan involving thousands of people including one of the world’s largest independent news organizations (the BBC); or 2. Get a small cadre of suicidal terrorists to hijack a couple of planes and fly them into the selected buildings? Because _even if_ we assume the Bush administration or some other shadowy organization was behind the 9/11 attacks, the simplest and easiest way to do it would be the second option above. Every other option is pointlessly complicated and far more likely to result in failure or exposure. ---
**Author:** ![dasmoocher](https://avatars.discourse-cdn.com/v4/letter/d/dbc845/32.png) [@dasmoocher](https://boards.straightdope.com/u/dasmoocher)\ **Post date:** [July 6, 2015, 2:50pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/107 "2015-07-06T14:50:30Z")
> [@Jackmannii](#): > > I don’t see why it had to be a rash. Skin cancers are more common in that age group. Or perhaps it was just an unsightly wart. > > I wouldn’t jump to the conclusion that it was a rash. > > Are there eyewitnesses to the condition of his skin on or just prior to 9/11? Have any of them mysteriously disappeared? To be fair, I was the one to speculate on a rash, but now that I think deeper on this, it could have been liver spots. As pointed out, Silverstein was pretty old at the time. I also think I know why **bombthefeds** is so fixated on WTC _ **7** _: From [www.numerology.com](http://www.numerology.com/numerology-numbers/7): > [@](#): > > The number 7 is the seeker, the thinker, the searcher of Truth (notice the capital “T”). The 7 doesn’t take anything at face value – it is always trying to understand the underlying, hidden truths. The 7 knows that nothing is exactly as it seems and that reality is often hidden behind illusions. Righteous! You go **bombthefed** s! ---
**Author:** ![Saintly\_Loser](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saintly_loser/32/4045_2.png) [@Saintly\_Loser](https://boards.straightdope.com/u/Saintly_Loser)\ **Post date:** [July 6, 2015, 2:52pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/108 "2015-07-06T14:52:00Z")
> [@bombthefeds](#): > > Just laying out the facts my friend, and addressing the claims of CT’s. > > In case you’ve notice I’m most interested in investigating the evidence not pointing guilt at Larry Silverstein or anyone else. > > I would actually love to let Larry and everyone else off the hook entirely, and hopefully we can find that the evidence matches up, and the whole thing really was just a demolition style collapse due to office furniture burning. What you’re saying here is flat-out _not true_. You’re not “addressing the claims of CT’s,” you’re _making_ conspiracy theory claims. This is just another form of JAQing off. And you don’t want to “let Larry [Silverstein] and everyone else off the hook entirely.” _He isn’t on the hook._ You’re the only one saying he is. You’re the one putting him on the hook. So don’t come in here and posture as if you’re defending him. ---
**Author:** ![Jane\_Elliot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jane_elliot/32/6166_2.png) [@Jane\_Elliot](https://boards.straightdope.com/u/Jane_Elliot)\ **Post date:** [July 6, 2015, 3:02pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/109 "2015-07-06T15:02:31Z")
> [@bombthefeds](#): > > It is the nature of the collapse. Evenly throughout the whole structure, all at once, accelerating into free-fall demolition style **collapse into its own footprint.** Into it’s own footprint? Did you even watch any of the video of the collapse that you linked to? There was massive destruction to buildings all around that area, and some of those buildings had to be demolished as a result. These were buildings that weren’t even in the World Trade Center complex. ---
**Author:** ![Mr.Miskatonic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mr.miskatonic/32/310_2.png) [@Mr.Miskatonic](https://boards.straightdope.com/u/Mr.Miskatonic)\ **Post date:** [July 6, 2015, 3:03pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/110 "2015-07-06T15:03:09Z")
In the interests of ‘completion’ and lest the OP accuse me of ignoring his 3rd ‘yes but’ example. > [@bombthefeds](#): > > Exhibition 3 > > [Fire Interstate Tower (now the Aon Center)](https://en.wikipedia.org/wiki/First_Interstate_Tower_fire) > > Photos: > > [Building on Fire](http://i.imgur.com/tLXD8lX.jpg) > > [After Fire](http://i.imgur.com/ec9rwZo.jpg) > > Now this building is very similar to WTC 7 in that it is a steel frame high rise. The fire cause of fire was suspected to be electrical though you imagine much of what was burning was “office combustibles.” > > **One of the main differences was the fact fire fighters were actively working to put this fire out, and the fire seemed to be spread across the entire building not on one side.** Yeah funny how that works. Firefighting! Who knew it could be so effective! I already debunked the OP’s repeated claims that WTC 7 fires were small. t’ain’t so. ---
**Author:** ![bombthefeds](https://avatars.discourse-cdn.com/v4/letter/b/77aa72/32.png) [@bombthefeds](https://boards.straightdope.com/u/bombthefeds)\ **Post date:** [July 6, 2015, 3:34pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/111 "2015-07-06T15:34:21Z")
Hey ya’ll just got back, okay looks like there was quite a stir while I was gone, I will address the points actually debating the science of the matter. Anything addressing motivation, character association or just plain disbelief I’m sorry I don’t have time to say anything about that. ---
**Author:** ![bombthefeds](https://avatars.discourse-cdn.com/v4/letter/b/77aa72/32.png) [@bombthefeds](https://boards.straightdope.com/u/bombthefeds)\ **Post date:** [July 6, 2015, 3:41pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/112 "2015-07-06T15:41:38Z")
I’m a little disappointed, there was only one person is still legitimately the point here. The rest of you are cute though 😛 > [@Mr.Miskatonic](#): > > Are you kidding me? Use explosives in lower Manhattan and people are going to notice. They are going to hear it. You can’t dismiss that with a hand wave. You are correct, which is why I presented this evidence earlier in the thread: > [@bombthefeds](#): > > The second reason cited has to do with sound. The report describes that if explosives were used people would have heard them because they would have needed to register at about 130db: > > The report then goes on to say that the sound recordings of the collapse do not demonstrate such loud explosions. > > Yet, [eyewitness reports contradict](http://rememberbuilding7.org/eyewitnesses/) this and then there are videos such as [this](https://youtu.be/0YvrKfWkxdw) and [this](https://youtu.be/0YvrKfWkxdw). > > Obviously no major explosion went off right before collapse, but eyewitness reports and videos such as the ones above show there is not conclusive proof that no loud explosions were heard within the last hour of the buildings life. > > OH LARRY, it’s not looking good for you buddy! The videos sound like explosives to me, and the eyewitness ports do concur. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [July 6, 2015, 3:43pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/113 "2015-07-06T15:43:16Z")
> [@bombthefeds](#): > > Hey ya’ll just got back, okay looks like there was quite a stir while I was gone, I will address the points actually debating the science of the matter. > > Anything addressing motivation, character association or just plain disbelief I’m sorry I don’t have time to say anything about that. You should definitely start hedging at this point about RL getting in the way and you don’t have time to look into everything. It’s the usual trajectory for 9/11 CT Truther types around here. Then you can quietly make your exit from this thread and we can go back to arguing other stuff with yet another 9/11 CT thread that future Truther types can ignore to bring it all up again. I’m sure everyone will be breathlessly awaiting your ‘debate’ of the ‘science’, which seems pretty cut and dried about WTC 7 (as well as the other towers that fell that day). I’m really hoping you bring up magic ninjas and fairy dust ‘nano-thermite’, though that’s generally more applicable to the other towers. Of course, if the WTC 7 was not brought down by the Occam’s Razor method of ‘fires burned out of control for hours after the building was hammered by falling debris from the collapse of the other towers’ thingy, then what DO you propose as to how it fell? And what evidence…‘scientific evidence’ to be sure…do you present? Or are you Just Asking Questions™ here?? ---
**Author:** ![Willcross](https://avatars.discourse-cdn.com/v4/letter/w/b2d939/32.png) [@Willcross](https://boards.straightdope.com/u/Willcross)\ **Post date:** [July 6, 2015, 3:45pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/114 "2015-07-06T15:45:07Z")
> [@bombthefeds](#): > > Hey ya’ll just got back, okay looks like there was quite a stir while I was gone, I will address the points actually debating the science of the matter. > > Anything addressing motivation, character association or just plain disbelief I’m sorry I don’t have time to say anything about that. Wait, I thought you were open to discussing motivation? That’s why you brought up the point about Larry Silverstein’s insurance policy? This seems like a big piece to the puzzle? ---
**Author:** ![bombthefeds](https://avatars.discourse-cdn.com/v4/letter/b/77aa72/32.png) [@bombthefeds](https://boards.straightdope.com/u/bombthefeds)\ **Post date:** [July 6, 2015, 3:51pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/115 "2015-07-06T15:51:45Z")
> [@Mr.Miskatonic](#): > > You miss the point. The collapse of the towers is what resulted in the fires starting in WTC7, ergo this is not a conventional fire starting. Convention fires tend to start in one location and move around. WTC7 probably had multiple fire starting locations. > > Steel loses starts to lose its structural integrity at much loser than 800C. At just 400c it [starts to weaken](https://fireworld.com/Archives/tabid/93/articleType/ArticleView/articleId/87379/Critical-Moments.aspx). So it doesn’t matter if the heat did not reach 800C. > > [No, it was not](https://www.youtube.com/watch?v=Afb7eUHr64U). Just because some 911 conspiracy kooks cherry pick photos of low smoke does not mean the fires were not out of control. The video I just linked to shows roaring flames and points where smoke is pouring out of windows on multiple floors. Tame is a relative term, which is one reason I cited those other skyscraper fires earlier, because those were most certainly out of control. The extent of the fire in WTC 7 is discussed and estimated in the NIST report on p32-37 (p74-79pdf). They also cite your number of 400 degrees: > [@](#): > > At both 3.5 h and 4.0 h, connections, floor beams, and girders were damaged or had failed at steel temperatures that were approximately 400 °C (750 °F) or less, primarily due to the effects of thermal expansion. After 4.0 h of heating, there was substantially more damage and failures in the WTC 7 structural floor systems than at 3.5 h of heating. But, again the model that ultimately derives from these calculations is not a very good fit to the visual evidence of how the building fell. The explosive models are probably much more accurate (though they did not release them, so how much more accurate we can only speculate). If you are satisfied with a model that looks very little like the actual collapse, well then there’s nothing more I can say. Considering this was only real contest to the discussion, this is probably all I will have to say anyway. Good day 🙂 ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [July 6, 2015, 3:53pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/116 "2015-07-06T15:53:00Z")
> [@Jane\_Elliot](#): > > Into it’s own footprint? Did you even watch any of the video of the collapse that you linked to? There was massive destruction to buildings all around that area, and some of those buildings had to be demolished as a result. These were buildings that weren’t even in the World Trade Center complex. It is clear that **bombthefeds** did not check the link provided. If there is another property that conspiracy theorists have is the one of reinventing the wheel. They continuously refuse to check how late they are with their “original” gotchas. It is very easy to check if that what they propose was already replied to thousands of times before so it is very easy to avoid making statements that will look really foolish… Alas. ---
**Author:** ![Mr.Miskatonic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mr.miskatonic/32/310_2.png) [@Mr.Miskatonic](https://boards.straightdope.com/u/Mr.Miskatonic)\ **Post date:** [July 6, 2015, 3:54pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/117 "2015-07-06T15:54:26Z")
> [@bombthefeds](#): > > I’m a little disappointed, there was only one person is still legitimately the point here. > > The rest of you are cute though 😛 > > You are correct, which is why I presented this evidence earlier in the thread: Sorry, but the use of explosives to demolish a building would have had everyone in lower Manahattan DEAF not just showing up as a bang on video. You don’t just fail to notice that, you would have hundreds of videos with multiple detonations, deafened first responders, and debris thrown all over the place. It just doesn’t even come close. I advise you strongly to watch the videos people posted of buildings that are actually being demolished and see what is involved. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [July 6, 2015, 3:56pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/118 "2015-07-06T15:56:12Z")
Who has got the master list of 911 threads? ---
**Author:** ![Mr.Miskatonic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mr.miskatonic/32/310_2.png) [@Mr.Miskatonic](https://boards.straightdope.com/u/Mr.Miskatonic)\ **Post date:** [July 6, 2015, 4:02pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/119 "2015-07-06T16:02:13Z")
> [@bombthefeds](#): > > Tame is a relative term, which is one reason I cited those other skyscraper fires earlier, because those were most certainly out of control. But were made of differing materials that were much more fire resitant, yeesh is any of this sinking in? You cannot miss a few elements and make a comparison. > [@](#): > > The extent of the fire in WTC 7 is discussed and estimated in the NIST report on p32-37 (p74-79pdf). > > They also cite your number of 400 degrees: And? > [@](#): > > But, again the model that ultimately derives from these calculations is not a very good fit to the visual evidence of how the building fell. According to who? > [@](#): > > The explosive models are probably much more accurate (though they did not release them, so how much more accurate we can only speculate). You are beggin the question again, sorry but such models cannot work. Not without magical hush-a-boom > [@](#): > > If you are satisfied with a model that looks very little like the actual collapse, well then there’s nothing more I can say. Engineers around the world seem quite satisfied with the model, including engineers in countries not freindly to the USA. But you, with no relevant degree to speak of somehow are smarter than all of them? I don’t think so. > [@](#): > > Considering this was only real contest to the discussion, this is probably all I will have to say anyway. > > Good day 🙂 Let me guess: you posted this same crap on some other forums, like a sports team forum and snowed them (or convinced yourslef you did) with a few layers of BS and came rolling in here full of yourself. Now you have been shown that you can’t even get some basic ideas down (like why you cannot compare one type of building design to another when it comes to fire vulnerability, and are marching off delcaring victory. ---
**Author:** ![Valgard](https://avatars.discourse-cdn.com/v4/letter/v/7feea3/32.png) [@Valgard](https://boards.straightdope.com/u/Valgard)\ **Post date:** [July 6, 2015, 4:14pm UTC](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340/120 "2015-07-06T16:14:41Z")
To the OP: I started a thread on this years ago, when NIST released their report on WTC7. I don’t have the thread handy but trust me when I say that we have done this topic repeatedly and in some detail. Trust me also when I say that you are not presenting anything new, nor are you asking questions that have not already been done to death here and elsewhere. Before we get into this yet again, I’ll give you my “credentials” for being able to have a reasonable discussion; I have my MS in structural engineering from one of the top CE schools in the world. I don’t claim to be an expert but I have the background to be able to understand what’s going on. What is your educational or work background in any relevant field such as structural engineering, fire safety, architecture or even (sigh) controlled demolitions? Taking a college physics class doesn’t make you an expert. You talk about the NIST report but as others have said, it doesn’t sound like you have actually read it. I did, all 130-odd pages. The abstract that you cited does not include the committee’s summary so let me post that. It’s really simple to understand and it’s thoroughly discussed in the body of the report. From p25 “The Leading Hypothesis”: -The conditions that led to the collapse of WTC 7 arose from fires, perhaps combined with structural damage that followed the impact of debris from the collapse of WTC 1. The fires were fed by ordinary office combustibles. -The fires on Floors 7 through 13 heated the building structure. Being lighter than the columns and with thinner SFRM, the floor beams, floor slabs, and connections heated more quickly and to higher temperatures than the columns. The elevated temperatures in the floor elements led to their thermal expansion, sagging, and weakening, which resulted in failure of floor connections and/or buckling of floor beams. -Sufficient breakdown of connections and/or beams resulted in loss of lateral support and buckling of at least one of the critical columns supporting a large-span floor bay on the eastern side of the building on or below Floor 13. This was the initiating event of the collapse. -The initial local failure progressed upward to the east penthouse. As the large floor bays became unable to redistribute the loads, the interior structure below the east penthouse collapsed into WTC 7. -Triggered by damage due to the falling debris and the loss of lateral support to adjacent interior columns, the failure progressed westward in the region of Floors 7 through 14, where the floors had been weakened by fires. This ultimately resulted in the collapse of the entire structure. Let me summarize this a bit: 1. WTC7 caught on fire. Ordinary office contents fed the flames. WTC7 may have also suffered structural damage when WTC1 fell down nearby. 2. Fires heated a number of the structural steel elements. The floor members in one area (7th through 13th floors) were thinner and had less fire resistant coating than the columns and so those horizontal members got hotter, faster compared to the columns. 2a. When steel gets hot it expands. The floor members expanded which weakened the structure in that area, caused failure in some connections and buckled floor beams. 1. Enough stresses from (2a) resulted in the loss of lateral support (bracing) of one of the long columns that was supporting a large-span floor. When a column loses lateral support the buckling load of that column (the axial load which will cause the column to fail in a particular manner) drops noticeably. Support was lost and the column failed. This started a local collapse in that part of the structure. 2. That local collapse spread upward. As the collapse continued and more of the structure was lost, the remaining parts of the building had a harder time supporting the additional load - no alternate load path. This resulted in a chunk of the east part of the building collapsing into WTC7 itself. 3. Failure progressed to the western part of the building in the already-weakened floors 7-14 area and eventually the whole building was lost. Do you have any questions about any of that? I don’t know what the constant refrain of “free fall time! 6s!!!” is supposed to mean. There’s a table in the report (it’s on p43) showing observed times of various events in the collapse. When the east penthouse began to fall is time 0sec. At 9.3 sec the west penthouse fell below the roofline. First of all it’s not like the whole building fell down in one single splat and second, what do people think is going to happen when you drop debris? Of course some of it’s going to fall at “free fall” speeds, it’s falling free. Some of it may not because the structure underneath is collapsing which takes time (admittedly not a lot of time) - it’s not as if it vanished in the blink of an eye. [Previous page](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340.md?page=5) [Next page](https://boards.straightdope.com/t/did-larry-silverstein-know-about-9-11/724340.md?page=7)