LANCASTER (CBSLA) — Authorities are investigating the cause of a deputy involved traffic collision in Lancaster around 3 p.m. Saturday.

A deputy from the Lancaster Station was traveling southbound on Sierra Highway — through the intersection at Avenue K — with red lights and sirens flashing.

READ MORE: Motorcycle Collides With Sheriff's Patrol Car On Interstate 105

As the deputy was about to clear the intersection, a civilian driver in a pickup — traveling eastbound on Avenue K — crashed into the passenger side of his patrol vehicle. The civilian was in the number three lane of traffic on a green light, officials said.

The violent crash — caught on dash cam video — caused the deputy’s vehicle to smash into two other vehicles stopped at the  red light that had been traveling north on Sierra Highway.

KCAL9’s Jeff Nguyen showed the dash cam video on the News at 10 p.m.

It shows a full-sized pickup truck broadsiding the black-and-white patrol car and glass flying before the patrol car continues to crash into two more cars.

Nguyen also spoke to one woman who was in one of those cars.

“I was at a red light,” says Noemi Martell, “All the cars had stopped because the cop car had his sirens on. That’s when the truck came in full speed. Didn’t see the cop car. Neither one stopped.  He T-boned the cop. And the cop swerved and hit us.”

READ MORE: Meeting Held To Help Curb Rising Violent Crime In Melrose Corridor

The deputy received a laceration to his forehead and some minor injuries. He was transported via ambulance to the Antelope Valley Hospital.

“He looked pretty beaten up. He was bleeding from his head,” says Martell.

Bartlett added the deputy is doing fine despite the hard impact.

“He’s doing good,”  says Lt. Paul Bartlett with the LA County Sheriff’s Department, “He’s doing good. He’s got some minor bumps and bruises. I’m sure he’s going to be sore tomorrow.”

The driver of the pickup also suffered minor injuries.

Bartlett says the patrol car was running a Code 3, which means its lights and sirens were on. He said the crash is a reminder to be careful on the road.

“Just be aware of your surroundings,” Bartlett says, “And slow down a little bit.”

MORE NEWS: FDA Authorizes Pfizer COVID-19 Booster Shots For Seniors And Others At High Risk

Anyone who witnessed the incident is asked to call the Los Angeles County Sheriff’s Department at (323) 890-5500. If you prefer to remain anonymous, you can call Crime Stoppers (800) 222-TIPS (8477) or by clicking on the Crime Stoppers website.