Flames whirled dangerously close to homes Tuesday as gusty Santa Ana winds sent the biggest of southern California's wildfires flaring in hilly brushlands on Los Angeles' northern edge and along subdivisions to the west.

Firefighters with hoses guarded houses as helicopters unleashed loads of water on hot spots of the more than 20-square-mile blaze charring slopes above the San Fernando Valley communities of Porter Ranch and Granada Hills.

Flames then pushed west to the rolling grasslands of Ventura County and made runs toward Simi Valley neighborhoods of modern homes defended by a broad firebreak, helicopters, airplanes and ground crews.

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The fire is one of three major blazes that have burned more than 34 square miles of Southern California, destroyed dozens of homes and forced thousands of people to evacuate their homes this week. One man died in the flames, and a motorist was killed in a crash as a fire neared a freeway.

Fifteen homes and 47 outbuildings were destroyed in the Porter Ranch area, and another six homes were damaged, said Los Angeles County fire Inspector Ron Haralson. Officials said the fire was 20 percent contained by 10 p.m. Tuesday, and evacuation orders for several neighborhoods, including large parts of Porter Ranch, were lifted.

"This was a preview of coming attractions," William Patzert, a climatologist at Jet Propulsion Laboratory in La Cañada Flintridge told the Los Angeles Times. "Now we're in a race with Mother Nature. What comes first? More Santa Anas or rain?"

"This is just the beginning. We're 10% through the season," he said. "People forget that Santa Anas are normal, natural and part of the history of Southern California."

Ten 10 miles away, there was major progress against Los Angeles' other big wildfire.

A 7 1/2-square-mile blaze in the northeastern San Fernando Valley was 80 percent contained and some evacuees were allowed to go home. But people who lived in an area where 38 mobile homes were destroyed were not permitted to return.

Teresa Escamilla, 47, lay on a cot in a Red Cross shelter, thinking the worst. She believed she lost everything including a shoebox containing five years of savings.

"It feels like it's not real," the nursing assistant said in Spanish. "It's a nightmare."

Mayor Antonio Villaraigosa acknowledged the uncertainty facing residents of the fire areas.

"Many still don't know when they are going to return home," he told a news conference. "Our hearts and prayers are out with all of them."

On the north coast of San Diego County, a 3,950-acre fire at the Marine Corps' Camp Pendleton was 60 percent contained. Most evacuation orders were lifted for residents of about 1,500 homes in neighboring Oceanside and many Marine Corps personnel and family members in military housing, but some remained in emergency shelters.

In eastern San Diego County along the U.S.-Mexico border, a fire burned 200 acres and forced residents from 300 homes in the community of Campo before it was contained Tuesday night. Firefighters kept watch for flare-ups overnight. Two were injured battling the blaze.

The outbreak of fires followed the weekend arrival of the first significant Santa Ana winds of the fall.

The National Weather Service said the intensity of the winds was diminishing but warned there would still be strong gusts. Warnings for critical fire weather conditions were to remain in effect until Wednesday night.

The Santa Anas usually sweep in between October and February as cold, dry air descending over the Great Basin flows toward Southern California and squeezes through mountain passes and canyons. The extremely low humidity levels, which make vegetation easier to burn, and high windspeeds combine to whip fires into infernos.