The Bobcat Fire increased in size slightly overnight — from 113,733 acres to 113,986 acres — and the containment expanded from 39% to 50%, forest officials said Thursday.
“Fire activity has moderated, and only 253 acres were added overnight,” Angeles National Forest officials said in a statement after daybreak Friday.
U.S. Forest Service officials, meanwhile, are investigating an equipment issue experienced by Southern California Edison around the time the fire broke out to determine if it was a factor in sparking one of the largest wildfires in Los Angeles County history.
Firefighters earlier this week successfully set backfires, including from the air, to destroy vegetation fueling the blaze and protect the Mount Wilson Observatory and several broadcast and telecommunications towers.
Firefighters planned to “continue to fortify the areas that were strategically burned to improve containment,” and some additional strategic burning may be necessary Thursday morning where the fire is pushing north, east and west, the U.S. Forest Service reported.
Reduced winds, lower temperatures and higher humidity reduced fire activity Tuesday, but Wednesday brought warmer and drier conditions, which were expected to continue Thursday, with southwesterly and up-canyon winds, according to the National Weather Service.
The fire, one of the largest in Los Angeles County history, is burning in the Angeles National Forest and threatening communities in the Antelope Valley and San Gabriel Valley foothills.
The Angeles National Forest will be closed through Oct. 1, the U.S. Forest Service said.
Flames have destroyed 52 structures and affected another 14, with three suffering minor damage and one suffering major damage, according to a damage assessment provided by Los Angeles County officials. That map, which is compiled from ongoing field damage inspection and subject to change, can be viewed at lacounty.gov/recovery/damage-inspection/.
Of the 52 buildings destroyed, 27 were identified as residential, one as commercial and 24 as “other.”
The fire has burned more acres than the Woolsey Fire of 2018, which scorched 96,271 acres, the Los Angeles County Fire Department said Tuesday. The Station Fire in 2009 burned 160,577 acres.
The fire came down from the Angeles National Forest into Cima Mesa, Juniper Hills, Pearblossom and Devil’s Punchbowl on Friday and damaged some structures, Vince Pena of the Los Angeles County Fire Department said Monday evening.
The Nature Center at the Devil’s Punchbowl Natural Area was burned by the fire, Los Angeles County parks officials said. The area is closed until further notice.
Evacuation orders were lifted and changed to warnings for the following areas:
— Clear Areas: north of East Avenue W-14, south of Pearblossom Highway, east of 155th Street East, west of 165th Street East;
— Sand Areas: north of Big Pine Highway and Highway 2, south of 138th Street East, east of Largo Vista Road, west of 263rd Street. The southwestern region of the Sand Area may have power outages.
— Ward Areas: north of Fort Tejon Road, south of East Avenue V, east of 87th Street East, west of 121st Street East.
Evacuation orders remained in place for residents:
— along Angeles Crest Highway, between Angeles Forest Highway and Highway 39;
— in the unincorporated areas and communities of Juniper Hills, Crystal Lake, East Fork of the San Gabriel River, Camp Williams, Valyermo and Llano (except for the Longview section, which is under an evacuation warning);
— south and west of Upper Big Tujunga Canyon Road, east of Angeles Forest Highway and north of Angeles Crest Highway
The following areas remained under evacuation warnings, according to the Los Angeles County Sheriff’s Department:
— Pasadena and Altadena: north of Sierra Madre Boulevard, west of Michillinda Avenue, east of Washington Boulevard, north of New York Drive, as well as north of New York Drive and Woodbury Drive, east of Hahamongna Watershed Park;
— Littlerock: south of Pearblossom Highway, north of Weber Ranch Road, east of Cheseboro Road, west of 87th Street East;
— south of Highway 2, north of Blue Ridge Truck Trail, east of Highway 39, and west of the Los Angeles County border;
— Longview: south of Avenue U-8, north of East Avenue W-14, east of 121st East, and west of 155th Street East;
— south of Pearblossom Highway, south and east of Pearblossom Highway, north and west of Mt. Emma Road, north and east of Angeles Forest Highway, and west of Cheseboro Road;
— south of Mount Emma Road, north of Upper Big Tujunga Canyon Road, and west of Pacifico Mountain.
The Wrightwood area in San Bernardino County was also under an evacuation warning.
A closure order has been issued for national forests in Southern California, including the Angeles National Forest.
A smoke advisory was extended through Thursday warning of unhealthy air due to the fire.
The South Coast Air Quality Management District said winds were predicted to move smoke from the Bobcat Fire to the northeast into the mountains of Los Angeles by Thursday afternoon, then out of the South Coast Air Basin.
The Bobcat Fire erupted on Sept. 6 near the Cogswell Dam and West Fork Day Use area northeast of Mount Wilson and within the Angeles National Forest.
The cause has not been determined, but U.S. Forest Service officials are investigating an equipment issue experienced by Southern California Edison that happened around the time the fire broke out.
The utility said in papers filed with the California Public Utilities Commission last week that it would remove a specific section of SCE overhead conductor in the vicinity of Cogswell Dam as requested.
SCE reported that “the Jarvis 12 kV circuit out of Dalton Substation experienced a relay operation at 12:16 p.m. on September 6,” but maintains that smoke had already been detected by a camera on Mount Wilson at 12:10 p.m. that day.
“While USFS has not alleged that SCE facilities were involved in the ignition of the Bobcat Fire, SCE submits this report in an abundance of caution given USFS’s interest in retaining SCE facilities in connection with its investigation,” the utility said.
A total of 1,613 personnel were assigned to the fire as of Wednesday night. Full containment is not expected until Oct. 30.