Why the towers collapsed: hit at vulnerable point

Salon ^ | 9/11/01 | Bill Wyman

[tet68]

I think they learned a lesson from the truck bomb which created a large crater but didn't bring it down.Someone with archectural training taught them how.

[PoisedWoman]

Fascinating. With both planes hitting at vulnerable areas, it sounds like very sophisticated planning took place. Who has the brains and money to do that? Bin Laden. Sadaam. And who else?

[habs4ever]

The most expensive commercial real estate in the world is no more.No other group of buildings could compare to its value or prestige.

[xm177e2]

We will have to rebuild the WTC in North Dakota, with 44 5-story buildings, each separated by a couple thousand yards.

Replace the rubble of the WTC with a memorial park, then burn down the UN building and make that into a memorial park as well.

[Sungirl]

Is Rush psychic? Cover of the Limbaugh Letter August 2001 Uncanny.

[Senator Pardek]

Not vulnerable areas - it was, as the article alludes to, the heat from the fire. A couple of hours ago, i ran into a guy who was 2 blocks away and saw the first tower collapse.

It was the sheer weight that did it after the metal melted.

[Alberta's Child]

Someone is going to be taking a serious look at the structural integrity of these buildings, especially since the structural engineer who designed them insisted at a recent conference that they were designed to handle a crash from a large passenger jet. It won't be easy to cover anything up here, since the most diligent people involved with the investigation will be the ones who work for the insurance companies.

My understanding is that the external tubular "lattice frame" was a new innovation at the time, and it was considered crucial in the design of any large structure because it minimized the amount of usable floor space that would be lost to internal columns. I don't mean to imply that the design was substandard, but I believe the World Trade Center was not required to meet City of New York building codes because the Port Authority of NY & NJ is a semi-autonomous agency that operates under its own regulations.

[RedBloodedAmerican]

Heat from the jet fuel melted away the internal support, and the top caved in, and collapsed the structure.

Thats it.

[_Jim]

think they learned a lesson from the truck bomb which created a large crater but didn't bring it down.

Ha ha!

You conveniently OVERLOOK those beams/columns DESTROYED by that bomb blast!

BTW, the author of this 'piece' overlooks the effects of heat (the fire) and it's effects on the materials involved (steel and concrete) ...

[Slip18]

Thanks for the article, LfD. It was a very interesting read.

Were there more than one "sect" involved in this hideous destruction of life?

[calebcar]

I hppe Bush gets together with Port Authority to rebuild the World Trade Center-updated as the tallest building in New York before the end of his administration.

[calebcar]

I hppe Bush gets together with Port Authority to rebuild the World Trade Center-updated as the tallest building in New York before the end of his administration.

[xm177e2]

This would suggest they have an engineer helping them, I'm still not convinced there are very many people involved in carrying out this attack, though.

[elfman2]

"He said that if the planes had hit the structures higher, they could have merely damaged their tops; if they had hit lower, they would have been up against the enormous weight and resistance of the base of the buildings. "

I doubt it. The planes would have taken down the towers if they had hit anywhere except the top floors. The structural support would burn away anywhere.

[independentmind]

I think they learned a lesson from the truck bomb which created a large crater but didn't bring it down.Someone with archectural training taught them how.

Interesting that you should say this. After the OKC bombing, there was a special group formed which examined this exact subject.

[Austim]

I hppe(sic) Bush gets together with Port Authority to rebuild the World Trade Center-updated as the tallest building in New York before the end of his administration.

If they were to rebulid it would you go to work at the new WTC?

[Real Cynic No More]

As a civil engineer with some experience in structural design, I don't agree with this analysis. They didn't have to be hit at a weak point. The columns would not have been designed for the impact. The momentum of the plane (velocity and mass) was so great that if it collapsed enough of the columns at the level it hit or at a lower level, the weight of the structure above is such that once it started falling on the collapsed level, its inertia and weight would have collapsed anything beneath it.

That's one problem I have with these forums, there's too much uninformed speculation out there, and then others repeat this as fact.