After replaying a few dozen times, it looks like a blade broke
off at near 10 o clock, the other two broke off immediately after that, and one of them struck the tower.
http://www.liveleak.com/view?i=cdd_1203701257
This thing is massive! The turbine is the size of a bus! Here's a
great pic to get some sense of scale:
http://tinyurl.com/36zy47