- Frank A De Martini (Manager, WTC Construction & Project Mgmt.): The building was designed to have a fully loaded 707 crash into it. That was the largest plane at the time.
- Richard Riggs (Debris Removal Specialist): The fires got very intense down there and actually melted beams and there was melted steel down there.
- Col. John O'Dowd (U.S. Army Corps of Engineers): In Oklahoma City you could see pieces of desks and chairs and there was something that told you this was an office building. At the World Trade Center site it seems that everything was pulverized.