I spotted this sign yesterday at the Perth Amboy, NJ train station.
Perth Amboy doesn't have an elevated train platform, with a drop down to the tracks; the train comes in right at ground level, and you climb steps up into it to board. Naturally, this makes it somewhat easier for those so inclined to leap in front of oncoming trains. So NJ Transit has apparently seen fit to create a suicide hotline, to prevent just such an occurrence.