It's amazing that that anybody survived this without life threatning injury.
A news chopper for WNBC-TV crash landed in Brooklyn. The helicopter had been covering a shooting at the time. It started to circle out of control, clipped a building, and landed hard on a roof crushing it like a tin can. Amazingly the pilot and reporter walked away from th crash.
The crash was actually caught on tape by another news helicopter.
http://abclocal.go.com/wabc/news/video/ ... ideo2.html
I'm no heli expert but it looks to me like a tail roter problem.