A 16-year-old girl was killed when she fell from a platform while apparently trying to catch a train.
The accident happened at Liverpool James Street station on Saturday night.
It is thought that the teenager, named locally as Georgia Varley, had been running along the platform after a Wirral-bound train following a night out in Liverpool with friends and family when she fell.
It is believed some of the party were already on board the train, which had begun to move away from the station.
A British Transport Police spokesman said: "BTP officers were called to an incident at James Street station in Liverpool at 11.34pm on Saturday.
"A 16-year-old girl from the Wirral sadly died after it is believed she fell between the platform and a train at the station.
"Officers are keeping in close contact with the girl's family and friends and our thoughts remain with them at this difficult time."
Police are speaking with a number of witnesses, including Merseyrail staff, and investigating the full circumstances surrounding the incident, which is currently being treated as unexplained.
Around 40 to 50 passengers were on the platform at the time of the incident and some were treated for shock by Merseyside Ambulance Service paramedics, police said.
The train involved was the 11.01pm Merseyrail service from West Kirby.