The train conductor killed him?
If you throw yourself in front of a train, there's no way the train can stop in time, and the poor conductor (or engineer, sorry) has to deal with the emotional impact of not being able to have stopped the train. They COULD, possibly, but it'd likely derail the train, so they don't. They don't slam on the brakes if someone stands on the tracks, because it would endanger all the rest of the passengers. Even emergency braking takes a fairly long distance, and normal braking can take miles. They just have to let it hit them, even if they see them standing there. And then the train has to stop for several hours for an investigation, often.
If it's a windows-front train, they get a nice view and hear the thumps and other unpleasant noises, too.
It is not the person killing themselves, it's putting someone else in a situation where they can't do anything but let the machine they're controlling kill them. It's selfish.