Photos by Cliff Albert, KOGO News.

The investigation was continuing into the cause of a four-acre brush fire that burned about four acres near homes near El Monte Road and Lake Jennings Park Road Thursday morning.

The fire helped knock out power to more than 9,500 customers.

Fire crews from several agencies rushed to the area and went on an all-out attack, stopping it just across the street from homes.

San Diego Gas & Electric officials say that despite initial reports from firefighters, the fire was not sparked by a transformer. 

No injuries were reported and no structures damaged.