About 300,000 vehicles use the freeway daily, California Governor Gavin Newsom said on Sunday, and the area is often clogged even under normal circumstances.
Newsom proclaimed a state of emergency in Los Angeles County in order to expedite repairs and he toured the damage on Sunday, vowing to get the freeway reopened as quickly as possible.
A section of freeway, also known as the east-west Interstate 10 or "the 10" in local parlance, is shut in both directions at a point between Interstates 5 and 110, two other major freeways that are vital to L.A.'s car culture.
The closure was likely to last several days, Los Angeles Mayor Karen Bass said.
Smoke billowed into the night sky after the fire broke out shortly after midnight on Saturday and it took 164 firefighters from 26 fire companies several hours to put out, the Los Angeles Fire Department said.
The fire spread through at least two storage yards underneath the freeway that held stacks of wood pallets and containers, the fire department said.
No injuries were reported and the cause was under investigation, the fire department said.
The governor's proclamation is intended to speed the repair work and clean-up and requires the California Department of Transportation (Caltrans) to pursue aid from the federal government if appropriate.
Caltrans engineers are assessing damage to both the support columns and the deck of the freeway to develop a repair plan, Newsom's office said in a statement on Sunday night.
Bass has also ordered all city departments to respond and said in a statement on Sunday that she had been in contact with U.S. Transportation Secretary Pete Buttigieg about hastening repairs.
(Reporting by Daniel Trotta; Editing by Noeleen Walder and Sandra Maler)
By Daniel Trotta
