California fire officials are investigating downed power lines and other utility equipment failures as possible causes of massive wildfires sweeping through wine country.
California Department of Forestry and Fire Protection spokeswoman Janet Upton says it's unclear if downed power lines and live wires resulted from fires or started them.
She said Thursday that investigators are looking into that and other possible causes.
Jennifer Robison of Pacific Gas and Electric Co. says the utility is focused on restoring power and maintaining safety. She says they will not speculate about the causes of the fires.
She says PG&E will support reviews by any regulator or agency.