On the bridgebuilder-game.com forum in the Offtopic channel there's a thread about the WTC....
http://www.forum.bridgebuilder-game.com/topic.c....Detail: the impact of the crash was no bigger than the load WTC was subjected to in high winds
Detail: WTC lost about 25% of vertical supports where the plane hit (don't know which tower, but should be roughly the same for each). It was designed to accomodate loss of 50%.
Detail: with only ordinary stuff burning (what was in the building), it should have stood up for hours - I guess that's what the firefighters expected. Kerosine burns very hot, and there were tons of it.
Detail: 1968 was a collapse of a tower that had the "domino" effect seen here as well. (When one of the upper floors crashes down, the load on the floor "catching" it is too great.) UK and other countries had building code in place that mandated design to consider this by 1972; the US took a lot longer.
If you want to test buildings for every imaginable disaster, why not include terrorist smuggling a nuke in there or a ballistic missile hit? You can't make evrything 100% safe unless you build a secret bunker,and even then there's the human element...
My heart goes out to victims of war and terrorists everywhere - be it in the U.S. or sponsored by the U.S. 