Report: Power lines sparked massive 2017 Southern California fire

An investigation has determined that one of the largest and most destructive fires in California history was sparked by power lines coming into contact during high winds.

The Ventura County Fire Department says Wednesday that the contact ignited dry brush on Dec. 4, 2017, and eventually blackened more than 440 square miles (1,139 square kilometers).

The Thomas fire destroyed more than a thousand structures in Ventura and Santa Barbara counties and resulted in the deaths of two people.

The report says the power lines operated by Southern California Edison created an electrical arc, which deposited molten material onto the ground.

Edison didn't immediately return a call seeking comment.

The investigation was conducted by county and state officials.