The locomotive/train caught fire, the driver bailed and the train continued on its own without an operator for about another 25km down the track of the Schwarzwaldbahn, until it was derailed and stopped on a commercial track at Gengenbach and the fire put out. As the train worked its way down the tracks it started several brush fires as it went.

I would have expected the driver to put the brakes on and bring it to a halt before bailing on the locomotive, not just jump out and let a flaming locomotive become a runaway. Maybe the problem in the engine compartment also involved or disabled the brake system.