First, the back story, because, B.J. Miller has found, the back story is unavoidable when you are missing three limbs.
Miller was a sophomore at Princeton when, one Monday night in November 1990, he and two friends went out for drinks and, at around 4 a.m., found themselves ambling toward a convenience store for sandwiches. They decided to climb a commuter train parked at the adjacent rail station, for fun. Miller scaled it first. When he got to the top, electrical current arced out of a piece of equipment into the watch on his wrist. Eleven-thousand volts shot through his left arm and down his legs. When his friends reached him on the roof of the train, smoke was rising from his feet.