From a testimony by a firefighter at WTC
Report from Ground Zero: The World Trade Center Collapse
Account of FDNY Lieutenant Brenda Berkman by Linda Willing, Associate Editor, WFS Publications (Women in the Fire Service, Inc.)
[…] After being ordered back because of the fear that yet another building was about to collapse (7 World Trade Center, 40+ stories), Brenda and her crew went to find other firefighters who might have some tools or a radio.
[…]That afternoon, 7 World Trade Center came down. "We had cleared an enormous collapse zone for that, and it still wasn’t big enough. When the thing came down, the rubble and the dust came across the West Side Highway, over and past the rubble from the towers that was there. We had to run."