Insurance companies have asked Southern California Edison to preserve evidence related to the devastating wildfires that hit Los Angeles, according to a company filing with regulators.

No fire department has suggested that the utility’s electrical equipment was involved in the fire, Southern California Edison said in the filing late Thursday. The utility said it filed an incident report “out of an abundance of caution.”

“SCE has received discovery communications related to the fire from attorneys representing insurance companies, and there are online publications that appear to indicate that SCE equipment may be related to the cause of the fire,” the filing states energy supplier.

The Eaton fire broke out Tuesday afternoon in Edison’s Southern California service area, according to a statement from the parent company Edison International. The fire has since burned more than 13,000 hectares of land and destroyed at least 4,000 buildings.

The utility said a preliminary analysis of circuit information for its energized transmission lines in the area showed “no interruptions or electrical or operational anomalies until more than an hour after the reported start of the fire.”

Shares of Edison International fell 10% on Wednesday as wildfires spread. The company’s shares fell nearly 2% in morning trading on Friday.