found these clips in the 9/11 archive that was published by http://archive.org. These videos were taken from the high quality MPEGs that were available for download for some time. Links are provided to high quality copies of this footage as well as links to the streaming versions on http://archive.org Showing the South side of WTC7, broadcasted by NBC at 1:45 PM.
http://video.google.ca/videoplay?docid=6186921835292416413
high quality XVID (640x480 de-interlaced) : http://www.megaupload.com/?d=CV4PU0IQ
link to http://archive.org (@ 22 minutes): http://www.archive.org/details/abc200109111323-1404
What is that black marking? It looks like a hole, but it seems much too smooth for being caused by falling debris. It looks to be at least 15 stories high.