As of 6 p.m., all evacuation orders will be downgraded to warnings, Cal Fire said. Residents are advised to remain vigilant and prepared for potential changes.
Cal Fire said road closures would continue to be enforced for nonresidents on South Corral Hollow Road and Chrisman Road south of Interstate Highway 580.
As of 5 p.m., westbound I-580 between Interstate Highway 5 and Interstate Highway 205 remained closed to traffic, though the I-580 eastbound is open, California Highway Patrol said.
The wildfire began Saturday at about 2:30 p.m. east of a Lawrence Livermore Laboratory site in San Joaquin County and reached 14,000 acres with 50% containment by Sunday afternoon, according to authorities.
SKY7 video shows aftermath of Corral fire burning in Livermore-Tracy area
SKY7 video shows aftermath of Corral fire burning in Livermore-Tracy area
Residents east of Highway 580 between Corral Hollow Road and South Tracy Boulevard were the first ones told to evacuate by the San Joaquin County Office of Emergency Services.
"Firefighters have made good progress constructing and improving control lines," CAL FIRE said on social media Sunday afternoon.
So far, PG&E says at least 171 customers are "de-energized," without power as of 10 a.m.
PG&E crews said they discovered six electric poles that were damaged by the fire.
Nearly 400 firefighters assisted by air tankers are fighting the fire, which started near Livermore National Laboratory Site 300 Saturday.
MORE: Tips for how to help and stay safe during and after a wildfire
Two Alameda County firefighters were hospitalized for treatment of minor to moderate burns Saturday, said Cheryl Hurd, a spokesperson for the department.
The cause of the fire wasn't immediately determined, Hurd said.
Site 300, covering 7,000 acres about 15 miles east of Lawrence Livermore's main site, is part of the laboratory's nuclear weapons stockpile stewardship program, according to its website.
The facility assesses the operation of non-nuclear weapon components through hydrodynamic testing and tests new conventional explosives for use as part of the nuclear stockpile, the laboratory said.
KGO-TV staff contributed to this report
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