The crash happened just after midnight on the southbound 5 Freeway at the Colorado Street offramp.
When firefighters arrived on the scene, they found the vehicle engulfed in flames.
The driver, who has not been identified, wasn't able to escape and died at the scene, according to the California Highway Patrol.
It's believed the driver was the only person inside the car. A SigAlert was issued for the closure of the SB 5 Freeway at the Colorado offramp.
The crash remains under investigation.