21.   Police said hospitals would start seeing more serious injuries as rescue workers started to sift through the rubble, a process that was made more difficult by falling debris.

22.   Putting a tank underground typically protects it from falling debris, and impedes leaks or tank fires from spreading throughout the building.

23.   Seconds later, flight controllers radioed signals to trigger another explosion and break the falling debris into smaller, less dangerous chunks.

24.   Seconds later, flight controllers triggered another explosion by radio to break the falling debris into smaller, less dangerous chunks.

25.   Sakowich kept an eye above for falling debris, while his fellow firefighters scrambled recklessly around the rubble.

26.   Six villagers near the launch site were killed by falling debris.

27.   Some dashed into the collapsing towers to pull out people trapped in the chaos and falling debris.

28.   Six police officers were taken to Jamaica Hospital to be treated for minor injuries apparently caused by the falling debris.

29.   Still within the range of the falling debris, Rembert stopped and turned.

30.   Ted Birkhahn, a spokesman for the City Buildings Department, said that no one was hurt and that the cause of the falling debris was under investigation.