The crash was reported shortly after 3 a.m. at Tustin Ranch Road, according to the California Highway Patrol. Only the far right lane appeared to be open.
Authorities said an SUV crashed into the concrete center divider, sending debris across lanes, including on the southbound side of the freeway. That car overturned and burst into flames.
At least one person was killed.
Additional details about the crash were not available. All lanes reopened around 7:30 a.m.
DEVELOPING: We will add more details to this report as they become available.