O_O
One part of the tracks is covered in sand for like 10 meters.
A train tries to go by there and it's going to derail.
Better send out some workforce to clean it up.
Oh wait...
Well, you see. They tried that, but it uh...didn't work out so well.
Turns out taking off prisoners' shackles and giving them dynamite isn't exactly an intelligent course of action.
From the appearance of the tracks it looks like they were able to coerce the prisoners to repairing them, but the trouble started when it was time to start clearing debris.