(Reuters) – Fire agencies are investigating whether utility infrastructure at Southern California Edison sparked a brush fire that is still burning in a Los Angeles suburb, SCE said on Friday, without determining done.

SCE, a unit of US utility Edison International (NYSE: ), said in a filing with regulators that a downed conductor was discovered on a tower associated with its Eagle Rock – Sylmar 220 kV circuit.

“SCE does not know if the damage observed occurred before or after the fire started,” the utility said.

SCE said preliminary information indicated that the circuit experienced a relay at 10:11 pm (0611 GMT) where the Hurst fire was reported at around 10:10 pm on January 7.

The Hurst fire, in Sylmar in the San Fernando Valley northwest of Los Angeles, has grown to more than 770 acres and is now 77% contained, according to the California Department of Forestry and Fire Protection.

Edison International did not immediately respond to a request for comment made through the company’s website.

SCE on Thursday said it had received notices from insurance companies to preserve evidence related to Eaton (NYSE:) Fire is still burning in Los Angeles, but said no fire agencies have linked the utility connection to the fire.

More than 10,000 structures were destroyed in the five fires that broke out in the area and nearly 30,000 hectares were burned.

Private forecaster AccuWeather estimated damage and economic losses at $135 billion to $150 billion, predicting a difficult recovery and rising homeowner insurance costs.