It was a wild, chaotic scene across a rugged swath of California's San Fernando Valley as fire season arrived with a vengeance.

Thousands of terrified residents waited until the last possible moment Monday to run for their lives, as dry Santa Ana winds ferociously whipped flames along the mountains and into hillside neighborhoods.

Even police and firefighters had to quickly abandon a command post when the unpredictable winds changed direction.

"The fire was nearly on top of us," said Los Angeles Police Department spokeswoman Mary Grady.

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Moments earlier, officers had been going door-to-door in a gated community of multimillion-dollar homes in the city's Porter Ranch area, urging stragglers to leave.

The homes were in the path of a massive wildfire that in just two hours had grown to cover more than 2,000 acres. As it spread, it rained hot embers and gray ash onto the neighborhood, setting palm trees on fire and producing billowing clouds of smoke.

Hours earlier, gusting winds sent flames charging down on the Blue Star Mobile Home Park.

Panicked residents had to smash their way through a locked emergency gate to escape after the main entrance became gridlocked with cars. Three dozen homes were destroyed.

In nearby Kagel Canyon, Renee Dunkel and her family armed themselves with buckets and a garden hose to try to keep fire from their home.

"We didn't think the fire was going to come over the mountain to us, but it was right there," said Dunkel, 33, who later took refuge at an evacuation center.

By midmorning, as that fire began to calm down, the mountains above Porter Ranch, noted for its stunning views of the San Fernando Valley, erupted in flames.

Pushed by wind gusts reaching 50 mph, that blaze whipped down hillsides so swiftly that it quickly turned blue skies as black as night.

Resident Dominic Dimitri stayed behind as long as he could, using a garden hose to battle a wall of flames that engulfed several palm trees on a ridge above his house. He finally had to leave when a cloud of smoke enveloped him.

"It was too smoky. I had to get out," a red-eyed Dimitri said from the street just outside his gated community, where he craned his neck to see if his house was still standing.

His sister, who also lives in Porter Ranch, told him flames were in her backyard when she finally fled.

"As long as you are safe, that's what counts," said Dimitri, 37. "It's fine to let the house go."