UPDATE 2014: Nathan Flach found the CBS national news version, with anchor Dan Rather, in a web file he saved before it was taken down. New York local Channel 2 was running their GM Building camera, where The Early Show was/is produced. A recording has been available thanks to the Dr. Ebbetts DVD collection “September 11th As It Happened” (link 2 above). See one replay in the TV archive: CBS9 at 10:48 am (better quality link 1 above).
This camera didn’t capture the South Tower event, apparently. As for the North Tower, there was also a missing CBS camera view: the Trump International Hotel & Tower that caught the 2nd plane hit at 1 Central Park West near the CBS Broadcast Center (at 530 W 57th St).
NIST Cumulus file: CBS2_clip42 (folder CBS_Broadcast_8-45A. No raw video available, only a TV broadcast recording.)
CBS2 (WCBS) View 1: GM Building

YouTube 1 & 2


