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SeaTurtle's avatar

What caused the collapse of world trade center 7?

Asked by SeaTurtle (1179 points ) March 21st, 2011

What caused the collapse of world trade center 7?
I’m not looking for theories, just science fact.
Do you personally have any scientific knowledge or education the subject? Not just what you learned via the media.
Please this is what I really want to know.

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29 Answers

BarnacleBill's avatar

This site does a pretty good job of documenting and explaining damage to WTC 7. There was more damage to the building than was apparent, as the photos show. WTC 7 contained 10 transformers at street level, 12 transformers on the 5th floor, and 2 dry transformers on the 7th floor. Electrical transformers explode when on fire.

SeaTurtle's avatar

Thank you @BarnacleBill but I really wanted scientific input on the subject, not counter theorist or conspiracy-theorist views.
(Just look at the propagandist dialogue and the minimalism of science in your link)

SeaTurtle's avatar

A link on an educated page like this would give your theories a case a defined structure cause and probability.

BarnacleBill's avatar

Fair enough, but the link that you provided brings up the subject of sound of explosions. The fact that electrical generators explode when under heat because they contain oil is a factual explanation. Are you looking for scientific evidence as to why oil is combustible under heat? Photographic evidence of structural damage far greater than presupposed is an important part of determining whether or not the building was structurally damaged.

YARNLADY's avatar

There are too many competing sites that purport to be the truth. I suggest you visit as many sites as possible, evaluate the sources, and make your own conclusion.

wundayatta's avatar

Here’s a theory that the building was brought down by shaped charges. But there is little evidence for the theory. The author thinks it is a sufficiently convincing theory that it should be studied.

Coincidently, this article came out exactly today. Your question should drive up the number of hits on that article. I’m sure Michael Fullerton, the author, will be very appreciative of your question.

Here’s The National Institute for Standards and Technology’s study—and their explanation of the observable evidence,

Here’s another person who thinks the official theory does not explain the evidence, but offers no other theory or evidence.

I’d be surprised to find evidence for an alternative theory. I think you’re on a fishing trip for something that may not be there. I also suspect that you already know that.

FireMadeFlesh's avatar

From what I have read, 7 collapsed due to instability caused by debris from the twin towers. The twin towers were over 400m tall, so falling debris could have reached a velocity of 90m/s (since the majority of the damage was low down). At this speed, it would rip huge gashes into the skin of the building, leading to instability in the floors. Once these fell, the whole building would come down. Damaged transformers would cause explosions, which would further damage the building.

Response moderated (Unhelpful)
hiphiphopflipflapflop's avatar

OQ: “Not just what you learned via the media”

Unfortunately, the manner in which scientific “facts” are disseminated and debated to the point that they are seen to be facts to at least some fraction of the community-at-large involves media too. Not a mass media, but a media regardless. Just try obtaining scientific journals for your University library and you’ll soon see what I’m getting at ($$$). If you believe in large-scale conspiracy theories, then the premise that these can be manipulated as well comes along quite naturally.

This is partly why these theories are essentially impossible to stamp out. Unless I was actually there in WTC 7 immediately before 9/11 and intimately familiar with the building structure and contents, I am relying on information promulgated by some form of media. The conspiracy theorist can always respond that my source of information has been manipulated. Or if I actually claim to have this intimate knowledge, then I’m a plant or I’ve been forced to toe the line by the conspirators!

Summum's avatar

There were many other buildings much more damaged by the debris from the twin towers. Also there was thermite found and molten medal in the basement of all three buildings. The metal was so hot it remained that way for weeks after and some of the rescuers shoes melted when going near the metal. A number of scientists and architects have computer software that analyses demolition of buildings. The software says that building 7 was demolition. The building fell at free fall speed which means there was no structure supporting the building as it collapsed in on itself. I have held samples of debris in my hands and saw it tested for thermite and it was present. Thermite or nanothermite is used to melt steel and make some of our weapons of war inoperable.

YoBob's avatar

As I understand it the floors of the tower were held up by trusses. As the fire spread several of the trusses in the center of the tower collapsed. So… what you are left with is four spindly legs that comprise the corner of the building suddenly loosing the center structural component that keeps them from twisting and collapsing. Once the trusses failed collapse was imminent.

Russell_D_SpacePoet's avatar

That is truly the million dollar question. If you look at the video of the collapse, it looks like controlled demolition. I mean what are the odds of a building like wtc 7 sustaining enough damage to be destroyed and when it falls, basically it falls into it’s own foot print. Also, what were the explosions that can be seen from several videos? They move up the structure in the same fashion as a controlled demolition. I think there is more to the story than the official line.

cockswain's avatar

There didn’t appear to be any plane wreckage at the Pentagon either, at least according to three documentaries I’ve seen. Nor any in the field in Pennsylvania.

The big question, is what the hell are any of us going to do about it?

Skaggfacemutt's avatar

My 31-year-old son is a conspiracy-theorist on this subject. And I, of course, thought he was just being his usual weird self. But when he told me that no plane wreckage was found in the Pennsylvania field or at the pentagon, I became curious and started looking on-line. It is true that I had never seen a photo of the wreck, or heard about the FAA gathering the pieces and putting them together in a hangar like they’ve done with every other crash. Hmmm… And what really raised a red flag for me is the totally stupid official explanation for the lack of planes. In the Pennsylvania field they said that the plane just burrowed into the ground like a dart in a sack of flour. And there was no explanation for the other one. Guess the powers that be didn’t see a need to give any explanation if the people are dumb enough to believe the ones they already gave. What a scary thought – kind of reminds me of the Kennedy assassination. Everyone at the time thought it sounded hokie, but we didn’t really put it together until years later.

YoBob's avatar

Hmm… here is a site that claims the photos at the bottom are of the plain wreckage inside the Pentagon.

As for Flight 93, the wikki page includes images of the wreckage.

Russell_D_SpacePoet's avatar

@YoBob How did that huge plane get through that hole in the side of the Pentagon? The plane shouldn’t have fit through that. At least it seems to me. 747 and 757 are huge. I was looking at the pic from your first link.

YoBob's avatar

Well, I don’t know @Russell_D_SpacePoet, what do you think made the hole and then left bits of aircraft strewn around?

Skaggfacemutt's avatar

I have seen a lot of plane crash photos in my time, and have never seen anthing that looked like this. I certainly hope that the conspiracy-theorists are wrong, but haven’t seen anything yet about those two crashes that seem in any way normal.

YoBob's avatar

I like a good conspiracy theory as much as the next guy. It’s just that when you have eye witnesses that saw a plane fly into a building and you have a bunch of totally mangled aircraft parts on the scene it tends to support the assertion that a plane was involved. Besides, IMHO, any credible conspiracy theory needs to include some sort of nefarious ulterior motive. Who gains what by blowing a hole in the side of the pentagon, dumping a bunch of aircraft parts around the scene, and then setting it ablaze?

Skaggfacemutt's avatar

Yes, YoBob, that was my argument, too. But have to go again back to the same ulterior motive as the Kennedy conspiracy. The government wanting a long, drawn-out, expensive war. To make money in war, you just have to have stock in a company that provides helecopters, tanks, ammo, or even mess kits to the military. Watch Schindler’s List. Or Gone With The Wind. War makes fortunes for the right people and paupers out of everyone else.

Russell_D_SpacePoet's avatar

@YoBob I don’t honestly know. I know I’ve seen many plane crashes and this one is anomalous compared to what I have seen. I don’t think there is enough wreckage for a 747 or 757.

Russell_D_SpacePoet's avatar

@YoBob Just read your other response to @Skaggfacemutt . The day before 9/11 Donald Rumsfeld announced that there was 2.1 TRILLION dollars missing from I believe from DOD. Is that enough of a reason to have a conspiracy? Because I never heard anything about the 2.1 trillion dollars after 9/11. Maybe destroyed some records? I don’t know. Just throwing that out there.

Summum's avatar

There were no plane parts that were discovered at the pentagon and there were 36 cameras that filmed the event and only 3 frames from two of the cameras was shown to the public. The hole in the side of the pentagon was way to small for a plane and there were no holes created where the two huge engines were on the planes. They even stated the heat was so intense that it burned up the engines which has never happened before but then they talk about finding remains of humans? If the heat was that intense there would be nothing human to identify.

kevbo's avatar

@YoBob, see here; for an eyewitness-based alternate “crash” scenario.

this video is available elsewhere (with fewer omg!!! type comments, etc), but this is the first link that came up.

Russell_D_SpacePoet's avatar

@YoBob Here is a motive.http://www.youtube.com/watch?v=OlnQTcLHaMM
It was 2.3 trillion btw.

kevbo's avatar

This is new. A career officer who survived the Pentagon explosion is taking Cheney, Rumsfeld, and Joint Chiefs Chairman General Myers to court over 9/11.

Summum's avatar

@kevbo Thanks for the link.

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