A motorist has been arrested on suspicion of drunken driving after her Kia sedan slammed into a car that was disabled in a crash with a CHP vehicle Sunday on the 605 Freeway in Norwalk, setting the second car ablaze and killing its four occupants, authorities said.

The crash occurred about 12:55 a.m. Sunday on the southbound freeway, just north of Rosecrans Avenue, according to the California Highway Patrol.

The decedents, who were occupants in a Nissan sedan, had been in a crash with a CHP patrol vehicle, which left the Nissan disabled, according to a CHP statement.

“While additional CHP officers responded, a second crash involving the disabled Nissan sedan, and a Kia sedan occurred,” according to the statement.

The Kia, driven by Iris Salmeron, struck the rear of the Nissan, which was in the No. 2 lane of the southbound freeway. The Nissan became fully engulfed in flames with four occupants trapped inside. Los Angeles County Fire Department paramedics pronounced them dead at the scene.

“During the investigation, officers determined Salmeron to be driving while under the influence of alcohol,” the CHP said.

She and another occupant inside the Kia were rushed to a hospital with major injuries, CHP Officer Zachary Salazar said.

Anyone with information regarding the crash was urged to call the CHP’s Santa Fe Springs office at 562-649-6800.