[valkyry1]

One thing that has never been played up (and it has always irked me) was that the design of those buildings played a large part into the collapse.

These buildings were not built like a Sears Tower (steel framed), they were built using a span and truss design with concrete poured over a wire mesh for the flooring. This type of construction while giving back a fast build time and lots of floor space, was never intended for such a tall building.

There was a Spanish steel framed skyscraper that completely burned out, and when it was all over the frame was still standing.

I am not saying a Sears Tower could completely burn out and still stand, but if we look at the parts of the WTC that started the collapse, then we are only looking at 15 or so stories where the collapse began, once it started there was no stopping it.

[naturalized]

Oh, please, stop. Those buildings withstood ridiculous amounts of kinetic energy and fire long enough to save thousands of lives. Those engineers and architects were heroes and the country owes them thanks it wasn't worse.

[EyeGuy]

I have never understood why those towers collapsed so easily. Thanks for the explanation.