Why did WTC 7 collapse?

[drummo]

I'm not a conspiracy theorist but this is indeed strange.

Is there any official explanation why WTC 7 collapsed?

Watch this:

http://reopen911.org/ad_vote.php?id=2

It indeed looks like controlled demolition.

This is another video showing a steel-concrete building burning in Madrid. It did not collapse.

http://reopen911.org/ad_vote.php?id=4

I know that the Twin Towers had unique structure but WTC 7 had a "traditional" steel structure. Why did it collapse all of a sudden?

[BlueEyedSon]

1. even if it was an "uncontrolled" demo, how did it come down?

[sabra]

2. there's a 9/11 forum here, lot's of experts there who could answer you ?

btw, welcome to DU!

[LARED]

3. Actually WTC 7 was unique

in that it was built to span over a substation, hence requiring some innovative design as "traditional" steel structure.

Many beleive that is a major factor in it's failure.

[drummo]

4. That's sound interesting.

Do you have a link to a detailed explanation?

[LARED]

5. Here you go

http://wtc.nist.gov/pubs/WTC%20Part%20IIC%20-%20WTC%207%20Collapse%20Final.pdf

[delver]

7. there is no explanation...what is a "conspiracy theory"?

you can see much of the evidence here:

http://www.wtc7.net


you can read archived articles from the New York Times here:

http://sneet.com/911/nytwtc7.html

it includes the following:

"But experts said no building like it, a modern, steel-reinforced high-rise, had ever collapsed because of an uncontrolled fire...Because of those doubts, engineers hold open the possibility that the collapse had other explanations, like damage caused by falling debris or another source of heat....A combination of an uncontrolled fire and the structural damage might have been able to bring the building down, some engineers said. But that would not explain steel members in the debris pile that appear to have been partly evaporated in extraordinarily high temperatures, Dr. Barnett said."

NIST will be releasing the "official explanation" in December, I believe:

http://wtc.nist.gov/

[pauldp]

6. Another question would be

why was all of the physical evidence from one of the most bizarre architectural failures in history (that looked in all of the videos not just sort of, but EXACTLY like controlled demolition) destroyed ? None of the steel was saved.


on edit: typo

[philb]

8. And who turned off the fire alarm system in WTC7 the night before 9/11 &

why?

see previous thread:

Its not clear what happened that caused WTC7 to collapse. But its clear that a decision was made very early to evacuate WTC7 before there was any damage, and to not fight the apparently small fires early in the day before the fires got bigger. Its not clear why those decisions were made, perhaps because a lot of firefighters had been killed in the other buildings and they didn't want more firefighters risking their lives fighting the fires in WTC7.
They did fight some fires in other buildings that had more structural damage and also worse fires. Those buildings did not collapse.
It seems to me that some effort could have been made early in the day, and abandon if no progress was being made and the task appeared hopeless. A fire chief thought they should have fought the fire.

[funflower]

9. How do you know it was turned off the night before 9/11?

[BushSpeak]

10. Why not accept Larry Silverstein's admission?

Larry Silverstein was the owner (or leaser) of WTC 7. He admitted on PBS that the building was pulled (controlled demolition) by the NYC fire department when they couldn't control the fire.

Only problem, how do you plant explosive charges in three hours!

This is on several of the 9/11 films and there are clips on several of the 9/11 sites.

You can get a free copy (or download) of "9/11: Confronting the Evidence" on the net.

I've had a hard disk crash, so I can't look it up now.

[vincent_vega_lives]

11. So the FDNY is in the demolition business now?

Only problem, how do you plant explosive charges in three hours!


That is a good question, especially in a building that has several floors ablaze, and most likely rather smoke filled.

Also you would have wires running everywhere. Radio control would be useless unless you didn't mind premature detonation due to spectrum overlap. NYC was a pretty signal rich environment that morning.

[petgoat]

12. "premature detonation due to spectrum overlap"

A non-issue. Simply have insensitive receivers so they would respond only to a very powerful transmitter.