In NYC one was supposedly a bad weld (that's what they said at first, but the piece was 24 years old, can't imagine it suddenly being bad after that long?) or a turntable that was put back into use that should not have been here is an article on that
http://www.nytimes.com/2008/06/01/nyregion/01collapse.html# .
And the other was some issues with the way it was strapped (not that I know what I'm talking about, not a crane person) - but in this case the INSPECTOR ended up getting his butt handed to him for not doing his job properly and being quite "crooked". Is the general gist of those two.
http://www.foxnews.com/story/0,2933,340035,00.htmlI think there's so many ways bad things can happen with a crane, bad things are bound to happen.
Improper maintenance, lack of inspection, improper usage, mistakes, and it's just plain dangerous.
When I lived up there, walking under those was a very SCARY thing to do..... things move FAST when they fall from that high.
Hope you at least find this informative. I'm really bored at work today....
Jenn