See Deputy Chief Peter Hayden’s interview in FireHouse magazine from 2002.
Originally Posted by Peter Hayden
"... but also we were pretty sure that 7 World Trade Center would collapse. Early on, we saw a bulge in the southwest corner between floors 10 and 13, and we had put a transit on that and we were pretty sure she was going to collapse. You actually could see there was a visible bulge, it ran up about three floors. It came down about 5 o’clock in the afternoon, but by about 2 o’clock in the afternoon we realized this thing was going to collapse.