In the early 90's there was a child that was screwing around on the backside of a bus after getting dropped off and they ended up dying. I think the bus ran them over by mistake. I was 11 or 12 when this happened, details are fuzzy, but I do remember the story.

Ever since then we've all been doomed with having a bus monitor check under the bus 3 friggin times to eb sure there aren't any kids under there.