A POLICE sergeant has died after being hit by traffic on a busy freeway, sparking a complete shutdown of all southbound lanes.

The heartbreaking accident occurred early Monday morning as Los Angeles police sergeant Shiou Deng exited his patrol vehicle on Interstate 405 in Brentwood to provide assistance to the victims involved in a car crash.

Deng, a 26-year veteran of the force, was walking over to the scene of the two-car crash when he was struck by traffic, LAPD Chief Jim McDonnell said.

The sergeant was rushed to UCLA Medical Center, where he died from his injuries.

Aerial footage from the crash site showed the airbags deployed in the heavily damaged pick-up truck and dark-colored sedan.

One person died from the initial car crash.

A second person involved in the two-car accident was transported to a local hospital in unknown condition.

Deng’s patrol car was left abandoned on the southbound side of traffic.

McDonnell, the LAPD chief, mourned Deng’s death, saying the veteran died a hero.

“He was out there every day caring for the most vulnerable in our society,” McDonnell told reporters outside of UCLA Medical Center.