one under

A term usually used amongst London Underground staff, a one under is a person who has either intentionally or accidentally become trapped underneath a tube train. This action causes large delays. Most one unders are suicide attempts, but occasionally accidental. A lot of one unders are fatal, but the 'luckier' people are just badly mangled by the sharp bits underneath the train. There are anti-suicide measures put in place on many London Underground lines including deep trenches and glass barriers. The trenches are so that people can't easily lie on the tracks and people who accidentally fall can protect themselves by lying in the trenches, and the glass barrier doors only open when a train is on the platform.