California ? The wildfire that has scorched 13 square miles and destroyed dozens of homes in the hills above this scenic coastal city was apparently sparked by a power tool being used to clear brush, investigators said Sunday.

Fire officials said someone, or possibly a group of people, was clearing vegetation on what appeared to be private land near the trail around the time the fire erupted Tuesday.

Some Santa Barbara County residents recently received annual notices advising them they had until June 1 to clear potentially hazardous brush, county fire Capt. Glenn Fidler said.

It was not immediately clear whether the blaze originated in an area targeted by such a notice.

Officials declined to comment further about the type of power tool that may have been used, or whether anyone could face charges.

The fire has destroyed 77 homes, damaged 22 others and forced the evacuation of approximately 30,000 people to safer ground.

By late Sunday, all but 375 residents from 145 homes had been allowed to return home and firefighters had the blaze 65 percent contained, aided by cooler, more humid weather.