BRENTWOOD -- A 67-year-old San Ramon man was killed in a three-car crash that closed Vasco Road on Monday afternoon, authorities said.

The crash was reported about 1:48 p.m. on Vasco Road about two miles south of Camino Diablo, according to the California Highway Patrol. A southbound 1999 Subaru driven by a man in his 20s apparently drifted out of its lane and into the northbound lane of the two-lane road, where it struck the guard rail, said CHP Sgt. Mark Firkins.

The car then swerved right, back into the southbound lane, and tried to correct its course, but overcompensated, swerving again into northbound traffic, where it struck a 1998 Mercedes on the driver's side.

The driver of that car was killed; a 67-year-old woman in the passenger seat received minor injuries, Firkins said.

A 1983 Pontiac struck the Mercedes from behind, but the driver, an 18-year-old woman from Watsonville, was not injured, Firkins said.

The Subaru caught on fire after the crash. Engines from Contra Costa Fire responded and extinguished the fire within about 20 minutes, a dispatcher said.

The driver of the Subaru was transported to a hospital with minor injuries.

Authorities are investigating what caused the Subaru to swerve into the guard rail.

The road was shut down from Camino Diablo to Dalton Avenue for about two and a half hours while the crash was investigated. The road was reopened to traffic around 5:15 p.m.

Contact Daniel M. Jimenez at djimenez@bayareanewsgroup.com. Follow him at Twitter.com/DMJreports.