It's sad because it's senseless, and because the victim had her whole life before her. But in truth, people older than 17 and with less excuse sometimes do equally dumb things.

If the teenagers thought about it at all, and they may have, they figured that a train probably would not come along, but that if one did come there would be ample time to get off the tracks. Obviously, there wasn't. If the spot was near a street or highway, as I suspect, the traffic noise may have masked the sound of the oncoming train. Today, unless we are railfans, we don't see trains very much, and we don't understand how fast they can be upon us.

The victim might have escaped, but she went back to get her purse. Talk about a bad split-second decision.