Bobcat Fire Possibly Caused By Vegetation Contacting Overhead Conductor

A fire that threatened the Mt. Wilson Observatory and placed Altadena and parts of Pasadena on evacuation warnings may have been caused by vegetation coming into contact with electrical equipment. 

The Bobcat Fire has burned 115,796 acres and is 92 percent contained. The blaze has destroyed 171 structures, including 87 residences, and damaged 47 structures, including 28 residences.

Although US Forest Service (USFS) investigators have not discussed the details of the investigation with SCE [Southern California Edison], the company told regulators, “SCE understands that in addition to retaining SCE’s overhead conductor, USFS also removed and retained three tree branches in the area.

“SCE is investigating the cause of the ignition and the 12:16 p.m. relay on its system, and evaluating whether vegetation in the area could have been a factor, including whether vegetation may have encroached within the minimum clearance distance or contacted the section of the overhead conductor retained by USFS.”

On Sept. 16, SCE removed a 23-foot-long line of the conductor for the U.S. Forest Service to use in their investigation.

More than 300 firefighters continued to work the blaze, which has been burning for over a month. The full containment date for the fire is projected to be Oct. 30.

The fire was reported near Cogswell Dam in the Angeles National Forest at 12:21 p.m. on Sept. 6. A camera at Mt. Wilson captured smoke in the area as early as 12:10 p.m.

Firefighters waged a desperate battle to save the iconic Mt. Wilson Observatory last month after the fire approached the historic structure.

On Sept. 14, workers at the observatory posted a letter on its website which said the Bobcat Fire was “rapidly” heading towards the observatory and could reach it that day.

“As of Sunday night, it has crossed the river at the bottom of the canyon, passed Chantry Flats, and is headed rapidly upslope towards Mount Wilson. The fire will probably be upon us today.”

The fire came within 500 feet of the observatory forcing firefighters to start backfires to absorb the fuel the fire would need to get closer to the observatory.

Meanwhile, Altadena and Pasadena residents received evacuation warnings. Some residents in nearby Sierra Madre were evacuated.

The Nature Center at the Devil’s Punchbowl Natural Area was destroyed, according to Los Angeles County parks officials.

A map, compiled from ongoing field damage inspection and subject to change, can be viewed at lacounty.gov/recovery/damage-inspection.

All evacuation orders have been canceled and most roads have been reopened, with the exception of Big Santa Anita Road (the Chantry Road).

The cost of fighting the fire has not been determined.