When the towers fell I was working as a Project Manager for a large construction company. We also had a division that did commercial fireproofing, by that time codes had totally changed, products as well. I was sitting with my boss watching the buildings burn as several discussed fireproofing and codes when the towers were built. My boss stated "I bet those towers collapse, they should clear the area out." It wasn't 10 minutes later the first tower fell.
Anyway, we all know Cheney planned this all, had all the buildings rigged to explode and timed it perfectly.