All but one lane of northbound state Highway 1 reopened tSaturday morning about four hours after a two-vehicle fatal crash in San Francisco, according to the California Highway Patrol.

Units responded to reports of a head-on collision at Junipero Serra Boulevard and 19th Avenue at around 4:25 a.m., CHP Officer Scott Cakebread said.

One man, who was driving alone, was killed in the crash and two other people who were in another vehicle were transported to an area hospital with life-threatening injuries, San Francisco police Officer Samson Chan said.

The Office of the Chief Medical Examiner identified the deceased as James Hunt, a 21-year-old Fremont resident.

A Sig-alert was issued at 5:24 a.m. All but the far left lane reopened by about 9:15 a.m.