Giuliani describes his experience living through the 10 seconds in which the south tower caved in and fell to the ground. This clip contains real footage from September 11, 2001.

Photojournalist David Handschuh recalls his experience during the September 11, 2001 attacks. He was taking pictures near the South Tower when it collapsed, which hurled him half a block and shattered his leg. He describes his experience being rescued.

This clip re-enacts the attacks of September 11, 2001. One of the flights vanishes off the radar, and air traffic control tries to communicate with it. As news starts pouring in of an attack on the World Trade Center, concerned air traffic controllers note that the flight is heading towards Washington D.C. and begin to suspect the worst.

Lieutanant McQuade explains the act of arson and their list of clues during his interview with Gabby and Tina.

The team investigate's the school's computer room after learning the smear flyers are printed out from there. There, they run into another student who they suspect may be the culprit.