LOS ANGELES — A wildfire in the mountains above Los Angeles has surged in every direction, going in a single day from a modest threat to a danger to some 10,000 homes.
The blaze nearly tripled in size in triple-digit heat Saturday, leaving three people burned, destroying at least three homes and forcing the evacuation of 1,000 homes and an untold number of people.
A slight drop in temperatures and an influx of fire crews from around the state were expected to bring some relief Sunday.
Mandatory evacuations were in effect for neighborhoods in Altadena, Glendale, Pasadena, La Crescenta and Big Tujunga Canyon.
The flames crept down the slopes of the San Gabriel Mountains despite mild winds blowing predominantly in the other direction.
“Today what happened is what I call the perfect storm of fuels, weather, and topography coming together,” said Captain Mike Dietrich, the incident commander for the U.S. Forest Service. “Essentially the fire burned at will; it went where it wanted to when it wanted to.”
Dietrich said he had never seen a fire grow so quickly without powerful Santa Ana winds to push it.
At least three homes deep in the Angeles National Forest were destroyed, and firefighters were searching for others, Dietrich said.
Evacuation centers were set up at two high schools and an elementary school in the area.
The fire was the largest and most dangerous of several burning around southern and central California and in Yosemite National Park.
The fire especially grew to the north and west, bringing new concerns for the areas near Acton and Santa Clarita.
More than 31 square miles of dry forest was scorched by the fire. It was only 5 percent contained.
At least three people were burned in the evacuation areas and airlifted to local hospitals, Dietrich said. He had no further details on their injuries.
Air crews waged a fierce battle against the southeast corner of the fire, burning dangerously close to canyon homes. Spotter planes and tankers dove well below ridge then pulled up dramatically over neighborhoods.
The fire was burning in steep wooded hills next to NASA’s Jet Propulsion Laboratory in northern Pasadena.
In La Vina, a gated community of luxury homes in the Altadena area, a small group of residents stood at the end of a cul-de-sac on the lip of a canyon and watched aircraft battle flames trying to cross the ridge on the far side.
At one point, the flying circus of relatively small propellor-driven tankers gave way to the sight of a giant DC-10 jumbo jet unleashing a rain of red retardant.
“We see a drop, we give a big cheer,” said Gary Blackwood, who works on telescope technology at the Jet Propulsion Laboratory. “We’ve watched it now for two days hop one ridge at a time and now it’s like we’re the next ridge.”
A major goal was to keep the fire from spreading up Mount Wilson, where many of the region’s broadcast and communications antennas and the historic Mount Wilson Observatory are located, officials said.
A second fire in the Angeles National Forest was burning several miles to the east in a canyon above the city of Azusa. The 3.4-square-mile blaze, which started Tuesday afternoon, was 95 percent contained Saturday. No homes were threatened, and full containment was expected by Monday.
A wildfire on the Palos Verdes Peninsula on the south Los Angeles County coast was 100 percent contained Saturday afternoon, according to county fire officials.
Southeast of Los Angeles in Riverside County, a 3 1/2-square-mile fire in a rural area of the San Bernardino National Forest was 30 percent contained as it burned in steep, rocky terrain in Beeb Canyon. No structures were threatened.
To the north, in the state’s coastal midsection, a 9.4-square-mile fire threatening Pinnacles National Monument kept 100 homes under evacuation orders near the Monterey County town of Soledad. The blaze, 60 percent contained, was started by agricultural fireworks used to scare animals away from crops. The fire destroyed one home.
A state of emergency was declared Saturday for Mariposa County, where a nearly 5.5-square-mile fire burned in Yosemite National Park. The blaze was 30 percent contained, park officials said.
Park officials closed a campground and a portion of Highway 120, anticipating that the fire would spread north toward Tioga Road, the highest elevation route through the Sierra. The number of firefighters was expected to double over the weekend to 1,000.
About 100 residents from the town of El Portal were under evacuation orders, said Brad Aborn, chairman of Mariposa’s Board of Supervisors. He said the remainder of the town, an estimated 75 people, were evacuated Saturday morning.