A teenager was killed when he climbed onto a railway line to retrieve an item dropped onto the rails.
British Transport Police said the 17-year-old stepped onto a live rail at Cobham station in Surrey just after 1330 BST.
They said the boy was with a younger girl at the time and after speaking to her they were satisfied there was nothing suspicious about the death.
Train services were disrupted for about two hours after the incident.
CCTV footage
Insp Chris Connell said transport police officers and Surrey Ambulance crews were called to the scene and police were given control of the railway line to deal with the incident.
It is thought the teenager was killed instantly.
His body was taken to Epsom Hospital where a post mortem examination will be carried out during the week.
Insp Connell said evidence, including the CCTV footage from the station, would be handed to the coroner to assist with his investigation.
South West Trains services on the Guildford to London Waterloo line were suspended, with some diverted via Epsom and the line was not re-opened until about 1530 BST.
Insp Connell said: "This is a tragedy and our sympathy and prayers go out to his family."