Three eastbound lanes of the 60 Freeway in Hacienda Heights were reopened Thursday night after a big-rig fire led to a rush-hour shutdown of the busy transportation artery.
The California Highway Patrol said it was not clear when the fourth eastbound lane would be reopened.
Westbound lanes of the freeway opened shortly before 9 p.m.
The blaze was reported shortly before 3 p.m.: The cab of the big rig, which was hauling compressed hydrogen tanks, caught fire as its driver headed east on the freeway. The woman driving the rig was not injured, authorities said.
The closure created a rush-hour traffic nightmare as vehicles flooded adjacent surface streets and the 10 and 210 freeways, which also run east and west across the San Gabriel Valley.
Eastbound traffic on the 60 Freeway was diverted to the 605 Freeway, and westbound vehicles were diverted at Azusa Avenue. The freeway is one of main arteries connecting Los Angeles to the San Gabriel Valley and Inland Empire.
After the cab fire was knocked down, firefighters continued spraying the tanks with tens of thousands of gallons of water. The water kept the tanks 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.