The California Highway Patrol said that a U-turn and a passing pickup resulted in the fatal crash over the weekend on a country road between Ione and Rancho Murieta.
Gerard Sprague, 19, of Concord died at UC Davis Medical Center from injuries suffered in the crash. Two others suffered major injuries.
The CHP said that Sprague was a passenger in a car driven by Adam S. Vanlandingham, 20, of Pittsburg, Contra Costa County, southbound on Ione Road, just south of Carbondale Road, early Saturday morning.
Jeffrey P. Allgeyer, 48, of Ione, approaching in the same direction, saw Vanlandingham's car stopped, according to the CHP. Vanlandingham was about to make a U-turn.
Allgeyer's pickup truck began to pass the car in the northbound lane when Vanlandingham started a U-turn, causing a violent crash of the pickup into the driver's side of his car, according to the CHP.
Vanlandingham, Sprague and another passenger in the car, Xavier D. Ward, 21, of Pittsburg, suffered major injuries. Sprague died later that same day.
Allgeyer suffered minor injuries. The CHP said only the drivers of the vehicles were wearing seatbelts.
The collision is still under investigation.