At least four people were killed in a fiery crash on the 605 Freeway in Norwalk early Sunday morning, according to the California Highway Patrol.

The CHP said that at about 12:53 a.m., near the Firestone Boulevard onramp on the southbound 605, a Nissan sedan and a CHP patrol vehicle were involved in a crash. The Nissan was disabled and remained in the roadway in the aftermath.

While additional officers were on their way to the site of the initial crash, authorities said a driver behind the wheel of a Kia collided with the back of the Nissan.

The Nissan burst into flames on impact, with all four occupants trapped inside.

All four people inside the Nissan were pronounced dead at the scene, the CHP confirmed. Their identities are being withheld by the Los Angeles County Coroner's Office, pending notification of next of kin.

Two more people were transported to a local hospital with injuries. One of them was transported in critical condition, while the other had minor injuries. The current condition of the critical patient remains unknown as of Sunday morning.

The driver of the Kia, identified as Iris Salmeron, was arrested on suspicion of driving under the influence of alcohol, the CHP said.

All southbound lanes of the 605 were closed in the immediate aftermath of the crash between Firestone and Rosecrans Avenue. They reopened by noon Sunday.

No additional details were immediately made available.

NOTE: The initial version of this story indicated that a Toyota Prius was involved in the crash. The CHP later clarified that the vehicle was a Nissan sedan. The story has been changed to reflect the new and accurate information.