San Diego

Two people, including a National City police officer, were killed and three others were injured Wednesday in a five-car accident that disrupted late-afternoon traffic along Interstate 15 for almost three hours, authorities said.

The accident occurred at 4:36 p.m. when, for unknown reasons, a car headed north on Interstate 15 at about 60 m.p.h. crashed through the center divider and into the busy southbound lanes near Carmel Mountain Road in San Diego, according to the California Highway Patrol.

The car hit the National City police car, which was going south, head on, authorities said. After the collision, the CHP said, the police vehicle burst into flames and hit two cars before it came to a halt, officials said. Another car was hit when a chain reaction ensued in the southbound lanes.

The officer, Robert A. Medina, 28, a resident of Chula Vista, was pulled from the burning wreckage by passers-by--including one woman with a fire extinguisher--but died at 6:41 p.m. at Sharp Memorial Hospital, where he had been taken by Life Flight helicopter, police said.

Medina was returning to National City after attending a parole hearing in Chino, authorities said.

A 79-year-old La Mesa woman was also killed in the accident and her 67-year-old husband was seriously injured and was to undergo surgery at Scripps Memorial Hospital in La Jolla, where he was listed in critical condition. He was driving the northbound car that police said initiated the accident; she was a passenger in the vehicle. Their names were not immediately available.

Two other occupants of another southbound car were taken to Sharp Memorial Hospital, where they were treated for minor injuries and released, a hospital spokeswoman said.

The CHP is investigating the accident. Traffic on the busy interstate did not return to normal until about 7:30 p.m., authorities said. Firefighters from San Diego and San Marcos responded to the incident.