September 11, 2001 - "CNN is now reporting that there was a third explosion at the WTC probably an explosion from the ground that caused WTC1 to collapse on top of itself. Again there was a third explosion it is unclear what caused it whether it was a bomb or whether the first plane that crashed into the tower had somehow been booby trapped with a bomb that was timed to explode later after the crashed had occurred. But CNN is reporting that there was a third explosion that caused WTC1 to collapse within itself".
Marcia Kramer, CBS2.
911datasets International Center for 9/11 Studies NIST FOIA NIST Cumulus Video Database\CBS2
Which collaborates with the newly realesed FOIA video of eyewitness testimony of Firefighters talking about secondary explosions in WTC.
9/11 FireFighters - THREE Explosions After Plane Hit WTC