There has been a lot of discussion about the crew and the locomotive fire and only in the last few days has the media reported that the entire train did NOT roll into town and derail. A look at the pileup supports this as there are not 70+ cars there and no locomotives. A network reporter delivered her report at the end of the cars remaining that are coupled to the locomotives at the siding and pointed out that this where the train separated.

It appears that cars rolled away after some type of action caused them to be uncoupled. I won't speculate here but this changes the story.