LOS ANGELES — The fifth-largest wildfire in California history expanded Tuesday, ripping through dry brush atop a coastal ridge while crews struggled to keep flames from roaring down into neighborhoods amid fears of renewed winds.
Elsewhere, fire officials announced that a cooking fire at a homeless encampment sparked a blaze last week that destroyed six homes in the Bel Air neighborhood of Los Angeles.
They are among a half-dozen fires that flared in Southern California last week and were driven by fiercely gusting Santa Ana winds.
Red Flag warnings for fire danger due to Santa Ana winds and a critical lack of moisture were extended into the week, with a possible increase in gusts Thursday into Friday.
Arson investigators determined that the Bel Air fire near the world-famous Getty museum was started by an illegal fire at a camp near a freeway underpass, city fire Capt. Erik Scott said.
The camp was empty when firefighters found it but people apparently had been sleeping and cooking there for at least several days, he said.
Northwest of Los Angeles, firefighters protected foothill homes while much of the fire's growth occurred to the north in unoccupied forest land, Santa Barbara County Fire Department spokesman Mike Eliason said.
"There were a couple of flare-ups in the hills that put on a light show last night, but they were expected. For now the teams are fighting the fire on their own terms," he said, adding that shifting winds were always a danger.
Tens of thousands of people remain evacuated, including many from the seaside enclaves of Montecito, Summerland and Carpinteria and the inland agricultural town of Fillmore.
Still among evacuees due to smoke Tuesday were Rock and Roll Hall of Fame member Eric Burdon and his wife, Marianna, of Ojai. Last week, Burdon wrote on Facebook about having to flee and returning temporarily to find their home still standing with ashes all around.
"A week like this gives you the perspective that life is what truly matters," he wrote.
A photo accompanying the post showed his handprint and signature written in ashes.
Residents near a Carpinteria avocado orchard said the trees could end up saving their homes.
"You have a thick layer of leaves underneath the bottom and they are watered regularly, so it's like a sponge," Jeff Dreyer, who lives nearby, told KEYT-TV. "So the fire gets to the sponge full of water and it slows it down. It takes a long time for it to burn."
Poor air quality kept dozens of schools closed. As ash rained down and smoke blew through streets, regulators urged people to remain inside if possible and avoid strenuous activity.
Officials handed out masks to those who stayed behind in Montecito, an exclusive community about 75 miles (120 kilometers) from Los Angeles that's home to stars such as Oprah Winfrey, Jeff Bridges and Drew Barrymore. Actor Rob Lowe was among residents who evacuated over the weekend.
The blaze — known as the Thomas Fire — has destroyed more than 680 homes, officials said. It was just partially contained after burning more than 360 square miles (930 square kilometers) of dry brush and timber. The fire has been burning for more than a week.
The fire is in an area of California that has remained in at least moderate drought even after last winter's powerful rains and heavy mountain snowfall eliminated drought symptoms in much of the rest of the state.