A California Highway Patrol officer and a suspect were shot on Interstate 680 near Walnut Creek this morning, and the freeway is shut down in both directions in the area of Livorna Road.

The shooting occurred at about 8:20 a.m. on southbound I-680 just north of the Livorna exit, and authorities are still looking into the circumstances of the incident.

CHP Sgt. Diana McDermott said both the officer and the suspect were critically injured and have been taken to hospitals. She said the officer is male, but did not have additional information on him or the suspect.

McDermott said it appears the shooting was preceded by a traffic stop, and that gunfire was exchanged by the CHP officer and the suspect.

She said the CHP is also investigating the "possibility of another individual that was on scene in another vehicle," but did not yet have specifics about that person.

Traffic in the area is at a standstill. Caltrans expects the freeway to reopen around 3 p.m.

"No one's moving," said 19-year-old Kayla McGowan, of Oakland, who got stuck in the gridlock as she was headed to a class at Diablo Valley College this morning.

Shortly before 10 a.m., she was still stopped on southbound I-680 near the where the shooting happened, and could see the yellow crime scene tape up ahead.

She said she had been in traffic for an hour and had missed her class. McGowan said motorists were getting out of their cars and socializing.

"Everyone's parked, just outside hanging out," she said.

— Bay City News Service

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