German researcher HerrKoenig recently discovered a forgery within the NIST CUMULUS Data-release, in the case of the WTC 1 collapse sound.

Listen yourself: This one was taken from the Naudet documentary DVD, by extrating the sequence to WAV and converting it into MP3-Layer3, 320kbps, 48.000 Hz with AVS Audio Converter 7.1.
http://www.911-archiv.net/category/4-artikel.html?download=22

This is from the NIST-release:
http://www.911-archiv.net/category/4-artikel.html?download=24

I have watched the Naudet film "9/11" carefully, but never noticed that it includes a clip of the WTC2 collapse that captures a dark smoke plume rising at a considerable distance apparently SW from the towers. No doubt its approximate location can be triangulated by reference to landmarks.

The plume does not appear to be industrial exhaust as it is dark grey and has not drifted laterally, but is typical of aircraft crashes.

It appears at 54:00 on the DVD, and blooms upwards for several seconds as the WTC2 cloud expands. A still from this clip is discussed as Item 5 here:

http://www.spingola.com/JULES%20NAUDET%20App%204.htm

The source of the clip is unknown and may be among the film's credits, but there it is--smack in the middle of this slick Naudet CBS/Paramount production.

I link to Raphael's analysis of the Naudet film "9/11" because it is the only place I have seen this still isolated, NOT because I seek to promote his conclusion that the film is evidence of complicity by the Naudets or--more devisively--certain members of the FDNY.