Hey Joe!
An old friend of mine that's been with the operating engineers since the late seventies told me that New York Crane - the company involved, have a tendency to cut corners so to speak, and he doesn't go on their jobs because of past experiences... He's got the seniority to pick and choose who he goes to work for so, it doesn't hurt him in the pocket - so to speak...
He was working one of those cranes at ground zero after 9-11-01 until most of the clean up was complete, and he's been working there on the new transportation hub as of late...
I don't claim to know what really happened or what really caused the accident, and neither does he but, he does know how New York Crane operates, and it doesn't surprise him much that the collapse happened or why it didn't happen sooner than it did. He chooses to remain anonymous.
Respectfully,
Henry