The first troop train from the North passed through Baltimore,Maryland, without incident.
VOA: special.2009.08.20
It explained that this was "because the previous train, an engineers' on-track machine, had passedthrough the crossing in the opposite direction to normal".
Passengers on the train in front were instructed by their driver to move through the carriages to the front of the tube as it passedthrough stations as the runaway gained on them.