A CHP officer is in critical condition and the suspect has died in a shooting along Interstate 680 Tuesday.
KRON 4 television is reporting the officer is on life support at John Muir Medical Center in Walnut Creek, but there has been no confirmation on that report.
About 10 members of the officer's family were seen leaving the hospital about 4 p.m. under the protection of security guards and CHP officers.
Law enforcement authorities were gathered all day long in an auditorium at John Muir Medical Center, where both the officer and suspect were brought after the shooting.
The wounded CHP officer has been on the force for seven years and was assigned to the Contra Costa County division out of Martinez.
Contra Costa sheriff's officials said two CHP officers in separate cars had made traffic stops on the right shoulder of I-680 near Livorna Road in Alamo at 8:20 a.m. when the gunfire erupted.
Sheriff's spokesman Jimmy Lee said the suspect was seated in a green Jeep Wrangler when he pulled out a gun and fired at the first CHP officer. That officer was critically wounded.
The second CHP officer then opened fire on the suspect, Lee said. That officer positioned himself on an embankment to shoot at the suspect, according to a Walnut Creek-to-San Ramon commuter who was driving on I-680 a short distance from the shooting scene.
Authorities are still investigating why the Wrangler was pulled over. Investigators are analyzing video from CHP dashboard cameras. The sheriff's office is investigating the case using "officer-involved" protocols, Lee said.
A number of motorists who witnessed the exchange of gunfire stopped. They were interviewed by investigators, Lee said.
Meanwhile, a second car that had been pulled over on I-680 at roughly the same time for a minor infraction apparently left the scene. Officers put out an alert seeking that car, a Nissan, "as part of due diligence," wanting to interview the driver, Lee said.
The car was located in the late morning in Danville and officers interviewed the driver, and "determined she was not related to this (shooting) incident," Lee said.
Shortly after the shooting, both directions of Interstate 680 were closed while authorities investigated the incident.
The southbound lanes of Interstate 680 in the Alamo area remain were closed all afternoon. Two lanes were reopened about 4:30 p.m. and all lanes were finally open again about 7 p.m. The northbound lanes were re-opened about 1 p.m.
Patch readers stuck in traffic emailed photos and commented on the post-Labor Day traffic jam. Some reported taking an hour to go one mile.
Traffic remains snarled along Danville Boulevard this afternoon. Traffic on Main Street and Broadway in downtown Walnut Creek was also jammed.
A traffic map and photos from the crowded freeway can be seen here.
At a press conference early this afternoon, CHP Sgt. Diana McDermott said her department is thankful for "all the calls and concerns" for the officer.
"It's a difficult situation for us," said McDermott. "We've had to really reach out to each other."
Are you stuck in traffic? Snap a photo with your phone and email it to David Mills, david.mills@Patch.com. To read more about what people are saying online about the shooting, click the link.