I think I read earlier that there was a locomotive at each end of the train. It’s possible that the one you saw on the tracks was the one at the rear of the train.
That's true.
The one that ended up down on the road was the head end and the one that stayed on the tracks was at the rear.
One of the newscasts said the trailing locomotive was dead, i.e. not running and just going along for the ride.
I don't know if that is true or not.