New regulatory filings shows power line surges, malfunctions during high winds, including at a transmission tower near where Hurst blaze began.

"The cause of the fire remains under investigation, and SCE continues to cooperate with authorities," the utility agency wrote.

Souther California Edison admitted that some of its sparking equipment likely started the Hurst Wildfire in Los Angeles last month. In a filing released Thursday, SoCal Edison said fire agencies were looking into whether its equipment could have been responsible for the Hurst Fire that tore through 800 acres of the Sylmar area.