I came across this newly released 9/11 image that has a shiny speck amidst the smoke and dust arising out of the crumbling towers. The speck looks
strange though I am not sure as to what it really is.
They had a line of helicopters flying over one of the towers (maybe both of them, not sure) before it collapsed, and you can see it on Rick Siegel's
footage.
There was speculation that the last one to fly over had an actual detonation device but who knows.