an Entity references as follows:
The Purley station rail crash was a train collision that occurred just to the north of Purley railway station in the London Borough of Croydon on Saturday 4 March 1989, leaving five dead and 88 injured. The collision was caused by the driver of one of the trains passing a signal at danger; he pleaded guilty to manslaughter and was sentenced to 12 months in prison plus six months suspended, although this was reduced to four months upon appeal, and in 2007 overturned. The Department of Transport report noted that the signal had a high incidence of being passed at danger and recommended that an automatic train protection system should be introduced without delay and in the interim a repeater for the signal that had been passed be installed.