YANKTON, S.D. | The death of a man found along a highway near Yankton has been ruled accidental.

A preliminary autopsy has found that Justin Arcoren, 18, of Chamberlain, South Dakota, was struck by a vehicle and died of blunt force trauma to the head and chest, according to a news release from the South Dakota Attorney General's Office.

Arcoren's body was found at about 2:30 a.m. Saturday along U.S. Highway 81, about four miles north of Yankton.