I know there was a thread on this subject and the last I read no one was able to confirm that it happened. The thread seems to be gone (I apologise if I just over looked it) but here is an article from the Star Ledger confirming it:
NJ Transit has put hundreds of its rail cars through special precautionary inspections during the past week after a wheel fell off a Main Line passenger train that had just finished its final trip of the night.http://www.nj.com/news/ledger/jersey/in ... 105160.xml
Train No.1119 was going less than 10 mph through NJ Transit's rail yard in Suffern, N.Y., when a wheel came off one of the passenger cars at about 7:30 p.m. June 17, transit officials said.
