SAN DIEGO — A man died Thursday afternoon when the pickup truck he was driving crashed into a metal guardrail on state Route 15, authorities said.

The crash was reported around 3:30 p.m. on southbound SR-15 near the Interstate 805 overpass, California Highway Patrol said in a news release.

The driver, a 43-year-old man from San Ysidro, was driving a grey Ford truck when it veered off the roadway and hit the guardrail in the center median, CHP said. The driver was ejected and died from his injuries.

CHP investigators were working to determine the cause of the crash.

The San Diego County Medical Examiner’s Office will conduct a toxicology report to determine whether drugs or alcohol were a factor in the crash.

Authorities have not released the driver’s name, pending notification of his family.