The engineer interviewed on the Nova show was Leslie Robertson, and I can still see the haunted look in his eyes as he talks about the destruction. The Nova site is still available:

Why The Towers Fell

There is a lot of information there about the innovations of the design. I remember the Towers going up, I had a close look at them from the air and simply thought they were ugly. I had no understanding of what went into them.

CarolC:

The Nova broadcast, which it turns out I still have on tape, did not go into the collapse of WTC 7. I can't speak to it other than repeat someone who said that the building sustained much damage in the collapse of its neighbors, WTC 1 & 2. S'posedly while a lot of photos from one side of the building shows it to be relatively unscathed, the side of the building I presume was facing the big collapses was structurally compromised and there are (supposedly) photos showing that side to be severely damaged.