It is apparant that Millennium Force went down due to mechanical reasons a few days ago before the park opened. Normally this would not be a big deal, however this time it was.
During test runs that morning the cable that returns the catch car in the lift system snapped and the catch car ended up continuing somehow of the top of the hill and down the other side. It dangled there for most of the day allowing for some pictures to be taken.
sorry that's the only pic I can find now