A female driver was killed when her SUV slammed into a tree on the side of the 91 Freeway and burst into flames, according to the California Highway Patrol.

The crash happened around 2 a.m. Wednesday in Cerritos just west of Pioneer Boulevard, the CHP said in a news release.

It’s not yet clear what caused the crash, but the driver was headed eastbound in her 2010 Honda Crosstour when she drove off the freeway into the tree, according to authorities.

“After the collision, the vehicle caught fire and became fully engulfed in flames,” the CHP said.

CHP officers headed to the scene, but didn’t arrive in time to save her from the flames, the news release said.

She had severe burns, and authorities are still trying to identify her, the CHP said. She was the only person in the car.

Investigators asked anyone with information about her identity or the crash to call the CHP Santa Fe Springs office at 562-868-0503.