From 9/11 Blogger
Looking through the newly released batch of videos from NIST and I found some interesting stuff in the folder "Richard Peskin." I have a edited together bits from four of the clips in that folder where you can hear what sound like explosions (after both towers have fallen), and the videographer (presumably Richard Peskin) saying that he's heard even more. They seem to be located around... Building 7. It all starts moments after the second tower collapsed.
The files I used were: Peskin 25.avi, Peskin 28.avi, Peskin 29.avi, and Peskin 30.avi.
See also: REVEALING NEW VIDEO: 9/11 Fireman Talk of Multiple Explosions, Black Plane