In Fahrenheit 9/11, "[o]ne disturbing vignette shows Bush in a Florida elementary school, dumbstruck upon learning of the Sept. 11 terrorist attacks, with a timer on the screen, clocking seven long minutes" (See USA Today story). The image below is apparently taken from the classroom two minutes after Bush has been told by Andrew Card that a second plane has hit the World Trade Center.
The video is available at The Memory Hole, republished here.