The documentary I saw on the building led me to believe asbestos WAS used on the support beams and on those latticing between the floors.
I saw another program about how they came down that implied the same. But they also said that it would only have extended the time before they fell. Still enough to have gotten more people out.
That's odd. I've seen documentaries showing that they didn't. But the area that needed to be insulated wasn't the vertical beams (though it would help). It was the horizontal connecting beams that 'unzipped' to cause the buildings destruction. When the horizontal beams became stressed, they detached from the vertical beams holding the building up. This put more stress on the remaining beams on the floor which rapidly failed. While the vertical beams may have been insulated, I very much doubt that the horizontal beams were.
Halfway through the construction of the first tower, environmental concerns did indeed force the builder to change the specifications of the sprayed on structural member insullation to something not including asbestos. The second tower was built with no asbestos spray at all, using the replacement. Failure Analysis shows that the CHANGE in insullation coating did have an effect... but had it not been changed it would have only extended the time a couple of hours... and you're right... more people would have been saved...