I've been reading some of the reports on the train derailment in Ohio. At this point, everyone is pointing fingers, but I haven't seen anything about it could have just been an accident.
I worked for years in, and out, of different rail car repair facilities. It was always interesting, and I learned a few things. One thing that caught my attention was a conversation with an inbound inspector at one of the facilities. They explained how the railroad companies didn't like dangerous cars, paid attention to any that were not incompliance, or needed repair, and would leave any they didn't like on a side track. Worse case situations demanded the cars were either repaired by a "mini shop", or placed on a flat car for a haul to a facility. If they felt a facility wasn't releasing safe cars, they could, and would, spike their switch. This was a serious matter, since no cars were allowed on their tracks until a problem was solved. This included any sections of rail they felt were unsafe.
Rail cars are owned by a multitude of different companies, and people. Individuals may own only one, and companies, or trusts, may own hundreds. All must meet requirements, and the rail companies don't like to get on the wrong side of AAR standards. The consequences are too expensive, and since all rails are owned by private concerns, there isn't a barrier to litigation like with the government.
So, accidents do happen. Ignoring the consequences, trying to assign blame to put feathers in a cap, trying to punish someone for an act of God, or trying to profit from an accident isn't good. Bearings wear, and fail, on rail cars. The rails can crack, or move, due to expansion and contraction. Nothing is perfect, and accidents can happen. The dangerous materials transported are usually well contained, safely being transported, and are never released during derailments. This one was a terrible one, and if there is any blame to be made, it's in the feckless way state, and federal, officials failed to address the immediate problems.