A Collection of Video Broadcasts of the Opening Moments of 9/11
Supposedly it wasn't expected but the BBC and all the major US
networks had cameras atop nearby buildings capturing footage
immediately after impact. ABC News even had a helicopter overhead.

http://belowgroundsurface.org/belowgroundsurface/framespage.htm?loc=http://below\
groundsurface.org/belowgroundsurface/Living911Part1.html

Ron

Candace: I was pretty amazed myself that morning how thorough the coverage was already a few minutes after the first tower was hit. Also, I think many of you know this now, but BBC announced the collapse of building 7 which occurred late in the afternoon, 20 minutes before it actually fell, giving away a huge clue of "preplanning".  Dark side always blows stuff, and thus give away the game. I haven't seen these video's, I will take Ron's word for it. The odd looking link above is correct, I tested it.