An 18-year-old man who had just graduated was being driven home by chaperones when he jumped out of a moving vehicle, RCMP said.
The man was seriously injured and unconscious when police arrived. He was rushed to hospital where he was pronounced dead.
The mishap occurred shortly before 4 a.m., about 15 kilometres west of The Pas in the Rural Municipality of Kelsey.
The man had earlier been celebrating with fellow students of the Margaret Barbour Collegiate Institute at the Carrot Valley Hall located west of The Pas.
The police investigation is continuing. The name of the man has not been released.