A man had died and a young child was injured when they were hit by a train.
British Transport Police said the incident happened close to a foot crossing on a stretch of track about 1km from Adwick station, near Doncaster, South Yorkshire, at 12.28pm.
A spokesman said: "The child was injured and has been airlifted to Sheffield Children's Hospital. The man was pronounced dead at the scene.
"Officers are currently working to establish the full circumstances surrounding the incident and to establish the identities of both the man and child."
He said the train involved was the 10.35am King's Cross to Leeds service.
The BTP spokesman said the girl, who is believed to be three years old, is in a critical condition.
The man who died is thought to be 28 years old and was from Bentley, near Doncaster. The incident happened on a stretch of track between Adwick and Bentley stations.