The origin 10-second collapse claim

[Minadin]

I was reading, as I am occasionally wont to do, over at the Screw Loose Change blog and I came across a post there, wherein a truther was making this oft-heard claim:

Near free-fall speed collapse of WTC1 (10 seconds), WTC2 (10 - 14 seconds)

Which we hear quite a bit, and I know we've timed it and we know it's not accurate. It's one of those long-debunked staples of the 9/11 conspiracy theory movement, and frankly it's one of the dumber ones, second only, in my mind, to their frequent statement that the collapses "violated the laws of physics." (this guy claims that as well) It's just so easy to prove untrue that I began to wonder why it's still around. But then, I started to wonder where it came from in the first place. Something this common and so demonstrably wrong must originate from the same source, right?

I started trying to track this claim by looking at the 9/11 commission report. Conspiracists seem to favor this document in comparison to more rigorous scientific papers, as it's written in more of a narrative format with less technical jargon. And, indeed I did find the old canard in the report, in section 9, Heroism and Horror:

At 9:58:59, the South Tower collapsed in ten seconds, killing all civilians and emergency personnel inside, as well a number of individuals-both first responders and civilians-in the concourse, in the Marriott, and on neighboring streets. The building collapsed into itself, causing a ferocious windstorm and creating a massive debris cloud. The Marriott hotel suffered significant damage as a result of the collapse of the South Tower.156

Of course, they make no similar claim for the North Tower, so it could be that our truther above is either mis-attributing the statement, has switched the tower numbers accidentally, or is getting his information from another source (who may or may not have gotten it from another source, who got it from another source, etc. ad nauseum, who got it from the 9/11 commission report, like a game of Truther Telephone^TM). But the most helpful thing is that they have end-noted a source for this claim. Perfect!

Note 156 for chapter 9 of the 9-11 commission report is as follows:

156. NIST report,"Progress Report on the Federal Building and Fire Safety Investigation of the WTC," June 18, 2004, appendix H, p. 40.

That's very convenient to look up, they even gave me a page number and everything! I found the progress report that they cited in about 3 seconds of google searching - it's on the NIST website, go figure - but it's also probably linked to here somewhere. (I honestly haven't taken the time to look and I apologize, but I stopped looking once I found it, and that was incredibly easy.)

According to page 40 of Appendix H of this report: (that's page H-40 as numbered at the bottom of the page)

Major events timed to an accuracy of 1 second are:​

• First plane strike on WTC 1: 8:46:30 a.m.
• Second plane strike on WTC 2: 9:02:59 a.m.

• Collapse of WTC 2: 9:58:59 a.m.
• Collapse of WTC 1: 10:28:25 a.m.
• Collapse of WTC 7: 5:20:52 p.m.​

However, it doesn't list the time ascribed to the collapse there, only the time of the collapse - and no mention as to whether it is the initiation or the conclusion of the collapse - though I suspect the former, as collapse initiation is what the NIST was studying. I could find no mention of the collapse times anywhere in the June 2004 interim report, which would have been the most recent one available to the commission. So, where did the 9/11 commission come up with the 10-second figure?​

A cursory search of these very forums provides some insight: many posters have linked to various helpful sources, though some are more recent than 2004. One of the sources cited includes -​

The NIST FAQ (2006):​

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2.​

This suggests that the times that both the commission and the conspiracy theorists are using are misapplied - they're using the times as building collapse times, rather than the amount of time that it took for the first ejected debris to fall - which we have all observed as falling faster than the buildings themselves, as evidenced by too many photographs and videos to mention here. The exact same section of the FAQ here even states that:​

From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.

Another is NIST NCSTAR-1, which comments on the events after collapse initiation in Section 6.14.4:​

Since the stories below the level of the collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos.

Now, we can argue as to what they meant by this more figurative language, but they don't seem to assign specific times of around 10 seconds here, either. And, in any case, this report came out in 2005 and cannot be the source for the commission's statement.​

I found R. Mackey's analysis of the collapse times versus "free fall" speeds of 10 seconds or so, and what it meant, which was great information and extremely informative, but brought me no closer to my goal of discovering the origin of this misinformation.​

So, I suppose that what I'm asking for is any information on where this 10-second claim might have first sprung up - how did the commission come to make that statement? Was it, as I suspect, an error caused by mis-reading some earlier version of the NIST estimate they have provided in their 2006 FAQ? Or, was it someone taking the "essentially free fall" comment a little too literally and doing some quick math with bad assumptions? Perhaps something else entirely?​

I am certain that if anyone has this sort of thing ready to hand, or knows where to look for it, it would be the members of this forum.​

 

[rwguinn]

You'll never make a good woo-woo...
The first law of twooferism is to read only as much as required to support your thesis, ignoring words that don't fit.
Thus,
"NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2."

becomes
"NIST estimated the elapsed times for the collapse initiated in each of the towers to be d approximately 9 seconds ."

because it fell as a single lump-all together, except for the pyroclastic flow, of course

sigh....
​

 

[MikeW]

The "about ten seconds" estimate was used in the press a lot, early on. Not with any attempt to measure it, it's just a convenient round figure.

 

[leftysergeant]

I am still not clear on one point. Was the speed of the first impact calculated from the time that it would take an object falling from the top of the tower to hit the ground? That would increase the speed of the collapse incredibly.

To properly measure the speed of collapse, one must start from the floor on which collapse started. This will shorten the time required for collapse at free-fall.

I have a hard time interpreting her data, but it seems to me that whacky old Judy calls the collapse happening at free-fall speed because it takes the same length of time for completion of collapse as it takes a billiard ball dropped from the top to hit the street. Garbage in-garbage out.

 

[Minadin]

Well, I suppose my question was really - Is there a common source for this "10-seconds" nonsense? And if so, what is it? Since it seems to have permeated into an "official" source, I had assumed that it might have been based on some sort of early "official" information - that may have been either misinterpreted or misread. But it sounds like the consensus is that it was just a ballpark type estimate that may have come from the media?

 

[leftysergeant]

Perhaps they are figuring it from the first noticeable jiggling on the seismographs. That appears to me to last about ten seconds before we see the really major spikes which, I have been told, represent either the first major debris hitting the ground or the detonation of the bombs.