NIST's Response to AE911Truth's WTC7 Girder Objection

[Sauron]

This is a video call of AE911 discussing some problems they have with the NIST report. In particular, the one discussed here on this very website.

I am unaware if Mr. Szamboti is the author of this specific objection. I am not versed in engineering and so do not understand the technicalities of this issue. I, therefore, will not attempt to explain the problem, which is stated as
'NIST’s 16-Story ANSYS Model Ignored the Effect that Column 79’s Side Plate Would Have Had in Preventing the Walk-Off of Girder A2001, Thus Violating the OMB Guidelines and NIST IQS”

That is not the point of this thread, which is NIST's airy dismissal, and whether the rigorous debunkers here find that worthy of an investigation into events of such magnitude.

I direct readers to the highlighted paragraph at 18:20 of the video https://www.youtube.com/watch?v=PcbIAJKV3Mk

To quote:

A. Column 79 Side Plate (page 8)

Your letter asserts that “NIST’s 16-Story ANSYS Model Ignored the Effect that Column 79’s Side Plate Would Have Had in Preventing the Walk-Off of Girder A2001, Thus Violating the OMB Guidelines and NIST IQS” and requests the following corrections:

Content from external source

(1) Revise the NIST WTC 7 Report to Reflect that the Column 79 Side Plate Would Have Prevented Girder A2001 from Moving Westward Enough to Walk Off Its Support at Column 79​

​

(2) Discard the Probable Collapse Sequence and Develop a New Probable Collapse Sequence that Is Physically Possible​

Content from external source

​

​

NIST disagrees that the 16-story ANSYS model ignored the effect that Column 79’s side plate would have on the walk-off of Girder A2001. The full-scale model has detailed connection models that are consistent with the fabrication shop drawings, as shown in Figures 8-21 and 11-15 of the WTC 7 report. The Girder A2001 and Column 79 connection locates the bolts on a seated connection attached to the exterior edges of the Column 79 side plates, with the girder axis at a slight angle to Column 79.

The 16-story model was based on architectural and structural drawings of the original building and subsequent building alterations, as well as erection and shop fabrication drawings (NCSTAR 1A, page 36), to ensure that the information used to develop the model was accurate, reliable, and unbiased. The model development was further informed by preliminary analyses of structural behavior, with consideration of loads, thermal effects, contact between elements, and potential failure modes. The 16-story model development complies with the OMB Guidelines and NIST IQS. Therefore, your request for correction to revise the NIST WTC 7 report with regards to the Column 79 and Girder A2001 connection and to develop a new Probable Collapse Sequence for WTC 7 is denied.

Content from external source

Source: https://www.metabunk.org/attachments/nist-response-2020-001-pdf.43235/

Here NIST simply says they disagree with the arguments presented, without any technical explanation of why. Just that all their schematics are correct, ergo no errors were made?

Whatever you think of the relative merits of the girder issue raised, this smacks of arrogance & intellectual laziness. Essentially saying that they don't think they made any errors & therefore don't see a reason to debunk them. That's a pretty shameful attitude to an obviously reasoned argument made in good faith. If anyone did that here, they would rightly be derided.

 

[Mick West]

This has essentially been gone over multiple times before in great detail. It's just a repackaging of old arguments.

It also seems to continue a misunderstanding of NIST's models. The 16-story ANSYS model was used to generate a damage model that was transferred to the full-size LS-DYNA model. This resulted in the detailed simulations of global collapse we are all familiar with.

Those simulations did not rely on the failure outlined in the "probable collapse sequence". There were multiple failures, all applied at once. Nit-picking about one of them - which was not that consequential to the global collapse model - is not something that demands a new inquiry.

NIST's model had limits - the damage would NOT have been simultaneously applied. But those were limits based on computing time and cost.

There are genuine questions about why NIST chose to promote a particular "probable collapse sequence" that did not match their actual 16-story model result. But those are not the questions AE911Truth is asking - seemingly because they don't fully understand the models.

I discussed this with Tony Szamboti, transcript and more analysis here:
https://www.metabunk.org/threads/wt...if-it-was-not-key-in-nists-global-model.9427/

 

[Sauron]

Thanks, pity that video has been deleted. The point of the thread is not so much the validity of the arguments, but whether NIST's response is adequate.

As you say here, do you not think they should do some more investigating, accepting it does invalidate the whole study?

Mick: Now, you've identified some problem with the simulation, and that's perfectly valid, that we should look at whether that's actually possible, if that girder did actually go off its seat or not. And it's possible that it did not. That is something that should be looked into. However that doesn't invalidate the entire study because the actual simulation that they used did not that as a necessary component.

Having simulataneous failures is not realistic regardless. A good investigation would indeed promote a particular plausible scenario to show it is at least possible to collaspe via the fires. If their promoted one has been shown to have problems, it needs re-investigating in my opinion.

 

[Oystein]

Seeing that...

...I am not versed in engineering and so do not understand the technicalities of this issue.

...I don't understand how you arrived at this particular judgement:

...That's a pretty shameful attitude to an obviously reasoned argument made in good faith. ...

You appear to imply that the "reasoned argument" is also a good, valid argument. How did you determine that?

A sincere, reasoned, but invalidly reasoned and obviously false argument ... ought to be rejected out of hand by NIST, wouldn't you think?
An argument made in bad faith ought to be rejected out of hand by NIST, wouldn't you think?

So now the question is indeed: Is the AE911Truth argument made in good faith, and is it validly reasoned?
I don't see how you would be in a position to judge that, without presenting an argument yourself. You say it's "obvious", but perhaps it is obvious to the competent engineers at NIST that it's not?

 

[Oklahomeless]

It seems to me that NIST is under no obligation to modify their models or change parameters in order to satisfy AE911. They’re not a governing body, they have no regulatory jurisdiction. All they can do is make a suggestions but, if NIST deems it baseless or invalid, it’s their call to make.

 

[Sauron]

Seeing that...

...I don't understand how you arrived at this particular judgement:

You appear to imply that the "reasoned argument" is also a good, valid argument. How did you determine that?

A sincere, reasoned, but invalidly reasoned and obviously false argument ... ought to be rejected out of hand by NIST, wouldn't you think?
An argument made in bad faith ought to be rejected out of hand by NIST, wouldn't you think?

So now the question is indeed: Is the AE911Truth argument made in good faith, and is it validly reasoned?
I don't see how you would be in a position to judge that, without presenting an argument yourself. You say it's "obvious", but perhaps it is obvious to the competent engineers at NIST that it's not?

Where in that quote did I imply it was a valid argument? As you say, I can't determine that.

(I can see in my 2nd post there is a typo where it should read 'accepting it does not invalidate the whole study')

If it is not valid, NIST should explain why. If it is obvious, then that should be very simple! Their response does nothing of the sort.

If they wanted to give Mick's refutation i.e

Those simulations did not rely on the failure outlined in the "probable collapse sequence". There were multiple failures, all applied at once. Nit-picking about one of them - which was not that consequential to the global collapse model - is not something that demands a new inquiry.

NIST's model had limits - the damage would NOT have been simultaneously applied. But those were limits based on computing time and cost.

they could have done so. But that still shouldn't satisfy the logical mind. To show collapse by fire is possible, let alone probable, they have to demonstarate at least one plausible route of getting there.

The one they chose to promote has subsequently been challenged with no obvious refutation, and they have rejected out of hand that challenge with zero intellectual curiosity. It calls, at the very least, for a review of that part of the investigation.

If NIST had posted their response on Metabunk, it would probably have been deleted for being off-topic.

 

[Mick West]

One elephant in the room here is that AE911 long ago threw away any credibility they might have. From NIST's perspective, they are essentially Flat Earthers raising subtle objections to the conventional model of the solar system while posting idiotic "globetard LOL" memes.

It would be great if NIST did a more thorough explanation, but after AE911 posted nonsense like the "Sideshow Bob" meme, they really shouldn't be expecting people to take them seriously.

 

[Sauron]

Yes that is asinine & in very poor taste. But NIST (and everyone else) should consider arguments on their own merits, & not invoke whataboutery.

 

[Mick West]

Yes that is asinine & in very poor taste. But NIST (and everyone else) should consider arguments on their own merits, & not invoke whataboutery.

Should NASA also consider flat earth arguments on their own merits?

AE911Truth are not helpfully pointing out inconsistencies here. They are aggressively promoting an idiotic theory of controlled demolition. I don't think NIST has any real obligation to humor them.

 

[Oklahomeless]

I’ve worked with a lot of high profile Engineers over the years and they don’t love to spend their time attempting to mollify their detractors. Unless AE911 have legit concerns made in good faith, they are not compelled to entertain them. They are not a client, consultant, or end-user. I have faith the modeling was done properly.

 

[Sauron]

Should NASA also consider flat earth arguments on their own merits?

AE911Truth are not helpfully pointing out inconsistencies here. They are aggressively promoting an idiotic theory of controlled demolition. I don't think NIST has any real obligation to humor them.

Yes they should, and they can very quickly show them to be baseless.

The wider objectives are irrelevant here. We're talking about a specific issue, which NIST dismissed out of hand, or at the most generous, rejected and did not show their workings. Either of which, I find unacceptable.

You are allowed to criticise both NIST and AE911 at the same time. It is not valid to reject arguments based on their wider implications, unless you have independently shown those to be false. And NIST does not claim to be doing this.

 

[Mendel]

If NIST had posted their response on Metabunk, it would probably have been deleted for being off-topic.

I don't understand how you make that determination. The NIST response indicates that they are aware where the side plate is located with respect to the girder, and that their full-scale model is modeling that connection. That directly refutes the claim that their model didn't consider this effect? What am I missing?

 

[Sauron]

I don't understand how you make that determination. The NIST response indicates that they are aware where the side plate is located with respect to the girder, and that their full-scale model is modeling that connection. That directly refutes the claim that their model didn't consider this effect? What am I missing?

That's not the claim being made. The claim is that it's not modelling it realistically. The fact that the response is counched in complete generalities suggests to me that they haven't bothered to engage with the material presented.

[removed off-topic material]

 

[deirdre]

We're talking about a specific issue, which NIST dismissed out of hand, or at the most generous, rejected and did not show their workings. Either of which, I find unacceptable.

does that hour long video (which has not been deleted) say that the lawsuit was dismissed by the Grand Jury?

I think the Grand Jury inquisition is relevant because either:
1. The grand jury is still on going in which case I'm surprised NIST was able to respond at all, but might explain the lack of detailed explanation you are oddly hoping for.
2. The grand jury dismissed the case (which sounds exactly like that letter you attached in the OP) and to me that means there is even less reason to explain. I would have said "you've already brought your hypotheses to a Grand Jury, stop harassing us." <ok i wouldnt have really said that, as there are protocols which much be followed in regards to public inquiries but i'd be thinking it.

 

[JMartJr]

Yes they should, and they can very quickly show them to be baseless.

You may be overestimating how open the Flat Earth believers would be to NASA's easy demonstrations that the flatist claims are baseless. In my experience, there is no simple and easy proof that will not be met with goalpost shifting, denial, and the like. And I am not even NASA, the bête noire of the flat Earth folks!

I have not spent as much time arguing with 9/11 "truthers," but I am fairly confident that they would respond similarly to NIST's assertions, however basic and simple to understand they might be, if for no other reason than NIST is the one making making them.

Responding to every single issue raised by such folks merely means that you get to spend the rest of your life arguing with people dedicated to not listening to you, and who seem to have a near infinite amount of time on their hands. "Should" they do that? I can't say that they are under any obligation to make it their life's work to chase goalposts all over the place. I suspect that they have enough work to do dealing with substantive issues related to their work.

 

[deirdre]

Responding to every single issue raised by such folks

just to clarify, for people new to 9/11 theories... they HAVE responded to every single issue. The problem is that AE911 (and flat earthers) keep bringing up the same issue(s) over and over and over.

 

[Mendel]

NIST are a government agency with a mission set by government, not by a lobby group like AE911.
There is no basis for AE911 to feel entitled to an answer from NIST that satisfied them.

 

[Sauron]

NIST are a government agency with a mission set by government, not by a lobby group like AE911.
There is no basis for AE911 to feel entitled to an answer from NIST that satisfied them.

Um yes they are obliged to rebutt an objection, which on the face of it, shows a mistake in their analysis.
To me this exchange is salient:

Mick: Yes, they may well have done, but my point here is that you are focussing just on this one connection. And your analysis of that one connection is pretty good. Because it's quite comprehensive, and you did identify a number of things, like the stiffener plates that were missing, and the differences in the width of the plate, and other things like the amount of thermal expansion, things like that, it's all valid. And that's something that in that limited case does actually make a difference. But what we've got to look at is the actual global case. And when NIST did it they didn't use just that one collapse of that one girder. They used a large number of other collapses of other girders.

Tony: I hear what you are saying. I saw you say this on the internet, okay, recently. But you have to be specific. You can't tell people we found some other areas where it collapses - well how did that happen? You have to show. They are not showing that.

That in itself would justify the need for a proper refutation or otherwise by NIST.

and then Oystein:

Hehe I opened a thread on this very topic at ISF (formerly JREF) a bit over two years ago - but it didn't get anywhere:
http://www.internationalskeptics.com/forums/showthread.php?t=304531

I raised the problem that NIST incurs all of the ANSYS connection failures at the exact same instance in the LS-DYNA model, when in fact they would have occurred at different points in time. This changes the dynamics of the collapse - significantly, I'd guess.

People are satisfied because they think the CD theory is bunk, not because NIST did a proper job.

 

[Keith Beachy]

Yes they should, and they can very quickly show them to be baseless.
...

No need, AE911T has no evidence. AE911T is spreading nonsense about NIST, when they need evidence to present to the FBI. Where is AE911T evidence? AE911T is a con, they makeup doubt to bilk gullible donors.

AE911Truth has no evidence to support their conspiracy theory. AE911Truth has no motive who did it, ignoring the 19 failed UBL diciples, no evidence against anyone beyond the fires not fought. When it comes down to reality, the only office buildings I know did not collapse due to fire, are fires fought. AE911Truth is stuck with WTC7 Fires Not Fought, and they made up conspiracy theories, short on evidence and facts.

Fires fought, buildings totaled ...
Windsor Tower (Madrid), fire fought, and the core was concrete, no global collapse, but steel only collapse in an hour or two.
One Meridian Plaza - The building was demolished in 1999, as a result of damage of a fire that began on February 23, 1991. The fire began on the 22nd floor and raged out of control for hours. Building totaled by fire, like WTC 7.

Why does NIST have to waste our tax dollars responding to conspiracy theorists who are only out to make money (over a million dollars) from gullible donors? Why?

AE911Truth has no evidence who did 9/11, they failed to check with the FBI. Why bother NIST, when AE911T know it was some inside job? NIST does not do Crime, FBI does Crime. I wonder why AE911T can't get the FBI to investigate? Because it is a simple fact, AE911T has the same evidence for WTC 7 "inside job thermite or whatever", as anyone has evidence for Bigfoot, and other frivolous fantasy conspiracy theories.

AE911T has no evidence.

 

[Mendel]

Um yes they are obliged to rebutt an objection

Why? Who will pay for them doing that, and how is that covered by their mission?

 

[Sauron]

Why? Who will pay for them doing that, and how is that covered by their mission?

It's a question of basic integrity. If they made a mistake, it needs correcting. And to determine if they made a mistake, they need to give this more than a cursory look.
Otherwise they could just have put out a load of rubbish, and people would be expected to treat it as the official story.

 

[benthamitemetric]

Um yes they are obliged to rebutt an objection, which on the face of it, shows a mistake in their analysis.
...

NIST directly rebutted the objection. You even quoted its direct rebuttal in your first post.

People are satisfied because they think the CD theory is bunk, not because NIST did a proper job.

Look to the professional literature, not to message boards. The NIST reports were ground breaking analyses at the time that used new technologies in careful and considered ways to explore an incredibly difficult problem. There have been no serious scholarly challenges to them published to date in the literature, even though we are nearly 15 years after the date of their first publication. Instead, they have been widely cited and built upon in subsequent research, and their many authors have continued distinguished careers in the relevant areas of expertise covered by the report.

 

[Mendel]

It's a question of basic integrity. If they made a mistake, it needs correcting. And to determine if they made a mistake, they need to give this more than a cursory look.
Otherwise they could just have put out a load of rubbish, and people would be expected to treat it as the official story.

The fun thing is that that's not even how academic science works. You don't have to answer every crackpot who complains about a detail in a decades-old analysis. What you need to take seriously is review by your peers, which typically means a rebuttal (a letter, or in more serious cases, a paper) in a peer-reviewed journal. I believe AE911 has never made it that far.

 

[Sauron]

The fun thing is that that's not even how academic science works. You don't have to answer every crackpot who complains about a detail in a decades-old analysis. What you need to take seriously is review by your peers, which typically means a rebuttal (a letter, or in more serious cases, a paper) in a peer-reviewed journal. I believe AE911 has never made it that far.

Yes good luck getting anything challenging the official 911 narrative into a journal. Academia these days is increasingly an echo chamber. You have given me an idea for non 911-specific thread.

 

[deirdre]

The fun thing is that that's not even how academic science works. You don't have to answer every crackpot who complains about a detail in a decades-old analysis. What you need to take seriously is review by your peers, which typically means a rebuttal (a letter, or in more serious cases, a paper) in a peer-reviewed journal. I believe AE911 has never made it that far.

NIST is a government agency. not a college or think tank. which is why they had a "public input" period before publication, and did look at and make some adjustments due to public input.

 

[deirdre]

this thread is World Trade Center 7. It wasn't hit by planes. and the NIST report says the damage to the building caused by the collapsing Twin Towers also did not contribute to it's collapse.

As I, a non-engineer, understand it, the "Official 911 Narrative" is that

(something like) untreated office fires that burned for many hours weakened such and such....

 

[Mendel]

Yes good luck getting anything challenging the official 911 narrative into a journal. Academia these days is increasingly an echo chamber. You have given me an idea for non 911-specific thread.

Yeah, that statement definitely deserves to be backed up with some facts, in a different thread. Otherwise it just sounds like sour grapes, assuming a suppression effort because the 9/11 truther theories are "challenging" instead of accepting that they have no merit.

 

[Jeffrey Orling]

The study of the causes of the collapse of 7wtc unfortunately required that the researches use reasonable assumptions for the "heat input data". There were no transducers to measure the heat, it's precise locations and duration. Based on the reasonable assumptions the girders was forced off its seat and that would lead to a local floor collapse and could initiate a chain reaction of structure failures leading to the complete collapse we witnessed.

But it should be noted that there are other possible "origins" of the initial failure which could produce the visuals we observed. Would it matter of the origin was at column 80 or on floor 15? I think not. We do know the sequence of the building movements and "know" that the failure was in the NE corner of the building as the EPH was the first visual sign of structural failure.

It also logically follows that the failures rapidly progressed from the NE quadrant westward involving the entire interior in structural failures. The structural design involving multiple "transfers" can account for the east to west progression.

These "debates" are essentially pointless. It is known how steel "performs" in elevated temperatures and engineers use various "strategies" to mitigate the impact of high heat... long enough for the building to be evacuated. The measures likely cannot "protect" the building from ultimately collapsing without fire suppression. In the case of 7wtc... sprinklers failed and there was no fire fighting to speak of. FDNY's responsibility was saving lives and when they determined the building was evacuated... they called for a safety zone around the building because their engineers saw tell tale signs of imminent collapse. They were correct. No tenants, occupants or fire fighter's lives were lost.

911Truthers have been prattling on for 20 years about controlled demolitions. There is no evidence to support these claims. THAT is 911 truth.

 

[Gamolon]

This is a video call of AE911 discussing some problems they have with the NIST report. In particular, the one discussed here on this very website.

I am unaware if Mr. Szamboti is the author of this specific objection. I am not versed in engineering and so do not understand the technicalities of this issue. I, therefore, will not attempt to explain the problem, which is stated as
'NIST’s 16-Story ANSYS Model Ignored the Effect that Column 79’s Side Plate Would Have Had in Preventing the Walk-Off of Girder A2001, Thus Violating the OMB Guidelines and NIST IQS”

That is not the point of this thread, which is NIST's airy dismissal, and whether the rigorous debunkers here find that worthy of an investigation into events of such magnitude.

I direct readers to the highlighted paragraph at 18:20 of the video https://www.youtube.com/watch?v=PcbIAJKV3Mk

To quote:

A. Column 79 Side Plate (page 8)

Your letter asserts that “NIST’s 16-Story ANSYS Model Ignored the Effect that Column 79’s Side Plate Would Have Had in Preventing the Walk-Off of Girder A2001, Thus Violating the OMB Guidelines and NIST IQS” and requests the following corrections:

Content from external source

(1) Revise the NIST WTC 7 Report to Reflect that the Column 79 Side Plate Would Have Prevented Girder A2001 from Moving Westward Enough to Walk Off Its Support at Column 79​

​

(2) Discard the Probable Collapse Sequence and Develop a New Probable Collapse Sequence that Is Physically Possible​

Content from external source

​

​

NIST disagrees that the 16-story ANSYS model ignored the effect that Column 79’s side plate would have on the walk-off of Girder A2001. The full-scale model has detailed connection models that are consistent with the fabrication shop drawings, as shown in Figures 8-21 and 11-15 of the WTC 7 report. The Girder A2001 and Column 79 connection locates the bolts on a seated connection attached to the exterior edges of the Column 79 side plates, with the girder axis at a slight angle to Column 79.

The 16-story model was based on architectural and structural drawings of the original building and subsequent building alterations, as well as erection and shop fabrication drawings (NCSTAR 1A, page 36), to ensure that the information used to develop the model was accurate, reliable, and unbiased. The model development was further informed by preliminary analyses of structural behavior, with consideration of loads, thermal effects, contact between elements, and potential failure modes. The 16-story model development complies with the OMB Guidelines and NIST IQS. Therefore, your request for correction to revise the NIST WTC 7 report with regards to the Column 79 and Girder A2001 connection and to develop a new Probable Collapse Sequence for WTC 7 is denied.

Content from external source

Source: https://www.metabunk.org/attachments/nist-response-2020-001-pdf.43235/

Here NIST simply says they disagree with the arguments presented, without any technical explanation of why. Just that all their schematics are correct, ergo no errors were made?

Whatever you think of the relative merits of the girder issue raised, this smacks of arrogance & intellectual laziness. Essentially saying that they don't think they made any errors & therefore don't see a reason to debunk them. That's a pretty shameful attitude to an obviously reasoned argument made in good faith. If anyone did that here, they would rightly be derided.

Do you actually understand what is going on here?

AE911's only objective is to keep brining money in for some of their members, mainly Gage. The only way to do that is to keep the demolition scenario alive and well and to continue to suck money from those people and groups who believe this nonsense. Do you really think that if NIST provided numbers/equations/explanations to rebuke their claim that it would all end? That AE911 would finally throw up their hands and say "NIST is correct"?

No way.

Gage would NEVER give in. He's got too much money to lose if they did.

Ask yourself this question. Do you honestly think AE911 is trying to correct a problem with NIST's report because they want to improve the understanding of how the buildings collapsed due to fire or are they just trying to build doubt in the report so they can further their demolition/conspiracy agenda and continue bilking folks of their money?

There is not one single shred of physical evidence that supports a controlled demolition. None. That's a fact.

 

[deirdre]

There is not one single shred of physical evidence that supports a controlled demolition. None. That's a fact.

or in the case of the Plasco building, which AE911 also claims could not have collapsed from fire. even though it did just that.

 

[Gamolon]

or in the case of the Plasco building, which AE911 also claims could not have collapsed from fire. even though it did just that.

Yup.

They had to claim demolition because folks were using/going to use that as an example of buildings collapsing due to fire.

 

[Sauron]

To be clear, I'm not a supporter of 911 'Truth'. I just think the arguments should be examined with sufficient respect, rather than dismissing on the grounds of who they are, as some here seem to think NIST are justified (or would be) in doing. At the least, they could have given an elucidated version of @Jeffrey Orling 's answer. They're obviously set themselves to be immune to any suggestion that their report was less than perfect.

@Gamolon why does it matter how AE911 think the buildings collapsed?

Even if you take it as a full-proof axiom that they collapsed by fire, a person being wrong about X does not make them wrong about Y.

 

[Oystein]

AE911Truth is of course aware that NIST's collapse initiation scenario is not the only one proposed by competent studies. In the course of the lawsuit involving Larry Silverstein, ConEdison, and the builders and designers of WTC7, the engineering firms ARUP and Weidlinger each presented their own versions - and each found a different "straw" that broke the proverbial "camel's back".

Which immediately means that at least two out of the three (NIST, ARUP, Weidlinger), and possibly all three, are mistaken about which particular, singular connection failure happened to be the first in a rapidly cascading collapse progression.
Interestingly, ARUP suggested that possibly the very same girder that NIST and AE focus on may have been pulled off its seat during the cooling cycle instead of being pushed off the same during the heating cycle.

What this shows us is that there are many different possible scenarios by which collapse may have initiated, all as a result of the fires, but difficult to be certain which actually did.
And in principle, this cannot possibly be ever known - many reasons, one of which that we don't actually know the exact conditions of the structure at the time the fires broke out (whether every single bolt, nut, plate was installed precisely as stated in design or erection drawings; how they might have deteriorated over time), nor the exact progression and intensity of the fires at every point in time.

AE accepts, promotes and sells a study (by Hulsey) which pretends there were fires on two floor only, and that those fires never progressed (wandered through entire floors, reaching maximum temperatures in various locations at various times, then cooling), and which ends up totally not having an explanation for the collapse at all. A study that fails to deliver on any of its explicitly stated objectives.

That's massively double standards.
Surely, AE is not about standards of excellence, accuracy or truth.