Investigators found power lines are the most probable cause of the 154-acre Emerald Fire, an Orange County Fire Authority spokesperson said.
Fire investigators shared their findings Saturday after concluding a five-month probe of the blaze that broke out in state lands north of Emerald Bay on Feb. 10.
“The most probable heat source was sparks from electrical arcing. High wind conditions and an unspecified electrical event among the three high voltage power lines caused sparks to be blown into a receptive fuel bed of vegetation,” OCFA Capt. Sean Doran wrote in an email.
Southern California Edison officials had not seen OCFA investigators’ report on the Emerald Fire by Monday night. They vowed to work with OCFA to better understand its findings.
“We know wildfires have a significant impact on the communities we serve and have been working to reduce the potential for wildfires through grid hardening, which includes installing covered conductor and targeted undergrounding of electrical lines,” SCE spokeswoman Diane Castro said Monday.
The announcement ramps up the heat on Southern California Edison as it also faces a lawsuit from Laguna Niguel homeowners devastated by the Coastal Fire on May 11. The fire consumed 200 acres and destroyed 10 homes in the Coronado Pointe neighborhood of Laguna Niguel. Another 11 homes were damaged.
The Coastal Fire’s cause remains under investigation. SCE notified the California Public Utilities Commission that its grid experienced “circuit activity” in Aliso and Wood Canyons Wilderness Park at 2:45 p.m. on May 11. In May, Laguna Beach entered into a non-disclosure agreement with county and state agencies regarding the inter-agency investigation of the Coastal Fire’s cause.
On Monday, Mayor Sue Kempf and Mayor Pro Tem Bob Whalen called on Southern California Edison to underground its infrastructure throughout the City, including along Laguna Canyon Road.
“Our number one priority is to protect the life and safety of our community from wildfire,” Kempf said in a press release Monday. “We will not stop pushing Southern California Edison to do the right thing and underground their utilities. If you look at the long-term costs of wildfire damage, it is millions and millions of dollars that utilities are incurring in some of these fires, these utilities are better off proactively undergrounding their wires now and eliminating the risk to life and property.”
Laguna Beach has lobbied Public Utilities Commission and state lawmakers to mandate utility companies underground their lines in communities within the California Dept. of Forestry and Fire Protection’s Very High Fire Hazard Severity Zone.
While speaking at a July 5 press conference in Los Alamitos, Southern California Edison CEO Steve Powell, shared the utility aims to harden about 40% of 10,000 distribution line miles in high fire areas by the end of this year.
“SCE remains committed to protecting our communities and most importantly partnering with fire agencies so we can be ready to mitigate fires right as they start,” Powell said. “We’re honored to partner with these fire agencies while they continue to save and protect the lives of our residents.”
The Orange County Fire Authority highlighted the work of its investigations team to explore the Emerald Fire’s cause.
“We would like to recognize our dedicated investigation services section for their resolute commitment to conducting a professional, meticulous, and exhaustive investigation on behalf of all the involved agencies, stakeholders, and our community,” Doran wrote.
This story is developing and will be updated as necessary.