There is a single party responsible when that person gets hit by a train*-- and that is the very person that gets hit by a train. Trains are not sneaky.
They do not attack with stealth or guile. They go where the rails go, and are limited in the speeds at which they can do so.
The fact that newer trains are quieter than old ones is not a defense. Are there two metal bars on the ground? Then assume a train is coming. It's spectacularly easy to
not get hit by a train.
Getting hit by a train requires a person to be in a very specific location at a very specific time... and not be paying any attention at all.
Once again, the train was the mechanic of death, complacency was the cause.
*there are those rare instances where the unfortunate victims played no active part in the event, like the San Bernardino Train Disaster of 1989. Those who lost their lives did so as a result of complacency, but it was not their own.