But he didn't believe there had been any mechanical failure.
To begin with, at least, it would be put down to mechanical failure.
State of the art, too - never had a mechanical failure.
He was running well until a mechanical failure dropped him to 36th.
He said the only other possible cause appeared to be mechanical failure.
Because a mechanical failure suggests that people weren't doing their job.
But safety board officials said again today that they thought mechanical failure was most likely.
And if a mechanical failure didn't stop them, lack of fuel would.
There was no evidence of mechanical failure on the train.
Police say mechanical failure has not yet been ruled out.