All lanes of the 60 Freeway in Hacienda Heights were open for the Friday morning rush hour after a big rig fire the day before temporarily shut down traffic in all directions.
Three eastbound lanes were opened hours after the fire was extinguished, with the last remaining lane opened about midnight, California Highway Patrol officials said.
Westbound lanes had reopened shortly before 9 p.m.
The blaze was reported shortly before 3 p.m. Thursday. The cab of the big rig, which was hauling compressed hydrogen tanks, caught fire as its driver headed east on the freeway. The driver of the rig was not injured, authorities said.
Thefire created a rush-hour traffic nightmare as vehicles leaving the freeway jammed adjacent surface streets and the 10 and 210 freeways, alternate east-west arteries across the San Gabriel Valley.
After the cab fire was knocked down, firefighters continued spraying the tanks with thousands of gallons of water to keep them cool while the compressed hydrogen was burning off through an emergency relief valve, Los Angeles County Fire Department Inspector Anthony Akins said.
The fire department said Thursday night that the tanks were largely empty and that emergency crews were in the cleanup phase.
The CHP said the tanks initially contained about 1,500 pounds of compressed hydrogen.