December 24, 2010:
FireTruckBlog.com (info and photos source) has a decent write-up with pictures.
Suddenly the captain in front dropped into the basement through a large hole in the floor. He was suspended by his shoulders on electrical wires, the only thing that prevented him from dropping fully into the basement. His partner was directly behind him and instantly transmitted a MAYDAY to Command.
The handline crew on the other side of the wall was now able to see just his head above floor level.