A woman suspected of driving under the influence and two passengers are dead following a crash on Highway 12 in San Joaquin County Sunday afternoon, the California Highway Patrol said.

A multi-vehicle crash in San Joaquin County on Sunday left three people dead and two others with major injuries, according to the California Highway Patrol. CHP said the crash happened at 3:40 p.m. just east of Clements Road at the Highway 88 and Highway 12 intersection.

The good Samaritan was standing near the right side of the GMC while attempting to assist the right front passenger and was struck by the Honda. The good Samaritan sustained fatal injuries and was pronounced dead, CHP said. The GMC and Honda became disabled, blocking the southbound lanes of Highway 99, north of Westside Boulevard.