[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.

[katykelly]

I was told today that if this is declared an act of war, insurance companies don't have to pay. I have no idea if this is the case. Maybe someone knows.

[Edmund Burke]

The buildings won't be covered by insurance if it is declared an "act of war".

[discostu]

Couple of quick things. One in the parlance of disasters "large passenger jet" generally refers to members of the DC series, the 7X7 series are "jumbo jets"; engineers are very into words and their full meaning, he was more than likely quite aware of this.

Two, the towers technically did withstand the collision, the ensueing fire probably did a lot of damage, warping the i-beams and generally weakened the structure.

Three, the guy said "a". The first tower hit was the last to fall, it's entirely feasable without the second collision it wouldn't have fallen; more than likely the shockwave of the first collision rattled through the entire structure (remember all 7 "buildings" used the same basement complex, they were very much attached to each other), probably weakening the entire thing, the second plane looks to have come in a little lower, able to do more damage to an already weakened building. Again the shockwave ran through the entire complex, exaserbating the damage to the first tower. The 2nd tower, apparently haveing taken more damage, collapsed first, again another huge shockwave.

Of course during all of this you have fire and gravity weakening the structure, you also have literally thousands of feet running down the stairs, making more vibration. Every piece of masonry that fell loose, every degree of fire heat applied to the structure, every second gravity was pulling down on the buildings, weakened the structure. Eventually gravity wins, it always does.

[Rome2000]

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.

These buildings met and exceeded all building codes, and they underwent continuous life safety upgrades over their 35 year existence.

The one thing the PA does well is spend a lot of money on safety.

[cinFLA]

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.

They both survived the crash. They probably did not analyze for the jet fuel fire!