Two 15-year-old girls died and a 13-year-old girl was critically injured after they were struck by a freight train in Utah.
Utah County sheriff's Sgt Spencer Cannon said the three girls were taking photos when they were hit on Saturday evening in Spanish Fork Canyon.
He said the teenagers apparently knew one train was coming, but did not realise another was coming from the opposite direction and became caught between them.
The Deseret News reports Essa Ricker and Kelsea Webster were killed in the accident. Kelsea's sister Savannah underwent surgery at a hospital on Sunday.
Sgt Cannon said one train either hit the girls or threw them into the path of the other, but it was also possible they were hit by both trains.
The area has two sets of tracks.