A lot of the fires started by trains, especially in the early days, were caused by what the railroaders called hot boxes. These were overheated wheel bearings which the old timers called journals. They often caused derailments and when this happened the whole crew was fired. The modern trains don't have this problem nearly as often because of better materials and maintenance.
My home town was a division point with the mainline running through so they had a turntable, for turning engines around, and huge shops for doing maintenance and repairs. It seemed like the yards were always full of cars and engines waiting for repairs.
My Dad was a conductor for years and they were the boss of the train crew. There were pretty big crews up there in the mountains and someone was almost always walking the car tops and checking for hot boxes. Way too often men were maimed or killed doing this. Nearly everyone of them had frost bite at least once on one or more hands or feet. There were a lot of knee injuries back then too and very little, short of amputation, to help them. After I got older and my Dad was long gone they came up with these modern knee braces and I've often wished there were such things back in the old days because my Dad had a real bad knee as long as I could remember.
Whenever one of the car walkers smelled a hot box the train would slow down and pull onto the nearest siding and drop the bad car, often ending up with the caboose in the middle of the train instead the rear. Quite a different world.