The wildfire that burned dozens of homes apparently was caused by someone clearing brush, officials said — the very thing authorities have been urging residents to do as a fire safety measure.

The 13-square-mile blaze was 65 percent surrounded early Monday after several days of cool, calm weather. Gusty winds that caused it to explode last week could return Monday night but not as fiercely.

Firefighters were mainly mopping up hot spots on Monday and carving containment lines in wilderness areas north of the city in Los Padres National Forest, Santa Barbara County spokeswoman Sarah Gibson said.

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"There is no open flame," Gibson said. "There are still open lines."

The area was enveloped by early morning fog but the National Weather Service forecast it would burn off later in the day. Evening could see winds of 15 to 25 mph with stronger gusts below passes and canyons.

Meanwhile, fire officials said sparks from a power tool being used to clear brush apparently ignited the so-called Jesusita Trail blaze last Tuesday. The fire moved slowly through high, dry brush until "sundowner" evening winds gusting to 50 mph and higher drove it into multimillion-dollar homes on coastal hillsides ringing Santa Barbara.

Authorities sought public help in identifying the person or persons who cleared brush on private land near the Jesusita Trail around the time that the fire erupted.

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

"Any time you use any power tool, there's always a possibility, especially if the conditions are right," said Joe Waterman, the overall fire commander from the California Department of Forestry and Fire Protection.

The fire has cost $9 million to fight, injured 28 firefighters, destroyed 77 homes, damaged 22 others and forced the evacuation of approximately 30,000 people to safer ground.

By early Monday, only about 370 people remained out of 145 homes.

Over the weekend, fire officials had praised residents for aggressively cutting back brush.

"More homes would have burned had they not done their defensible space work," Santa Barbara County Fire Chief Tom Franklin said.

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.

In 2005, after a series of devastating wildfires in five counties, California extended its clearance requirements for homes in forests, mountains and brushy areas in an effort to bolster the defensible space needed to protect a house from a wildfire and keep firefighters safe while working.

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