After forcing thousands of Californians to evacuate and burning more than 100 structures, a stubborn wildfire burning northwest of Los Angeles on Friday challenged firefighting crews working to snuff it out even as fierce winds in the area calmed.

Overnight, the area scorched by the blaze — dubbed the Mountain Fire — remained at about 20,000 acres in Ventura County. Containment was estimated at 7%, compared with 5% on Thursday, Cal Fire said in an incident update.

“The fire is burning in steep, rugged terrain, with dry and receptive fuels, which have challenged containment efforts,” the agency said. “Fire activity moderated due to the decrease in winds over the fire.”

Cal Fire added that the fire remained a threat to critical infrastructure and that islands of unburned fuel would continue to burn within its footprint.

Among those who lost a home to the blaze is Dennis Gottlieb of Ventura County. He counted himself lucky to be alive as he waited early on Friday morning at a shelter at Padre Serra Parish Catholic Church in Camarillo, California, wondering what to do next. He lost everything but his truck.

“It was windy, real windy, but that’s all, so I just started my regular day until I saw the smoke and then the fire,” he said. Gottlieb grabbed some garden hoses and thought he could keep the blaze away from the house if needed.

“Suddenly the smoke got real heavy and embers were falling all around,” he said. “It was hot, real hot, like 150 degrees (65 C). So I grabbed the keys to my truck,” he said. He and his wife, Linda Fellerman, barely made it out. One road was blocked by a fallen tree until a neighbor with a chainsaw cut it away.

He went back on Thursday to see if he could salvage any keepsakes but said “Everything is gone. All gone. Burned up.”

A red flag warning remained in effect for the area until at least 11 a.m. when winds were expected to calm to less than 15 miles per hour (24 kph) and humidity was due to climb, the National Weather Service said.

On Thursday, more than 10,000 people were ordered to evacuate from neighborhoods near Camarillo, about 45 miles (724ed4e km) down the Pacific Coast from Santa Barbara. Afterwards some homes were set ablaze by embers blown from the fire as winds gusted up to 80 mph (130 kph).

More than 130 structures were lost in the fire, the Los Angeles Times reported.

“The only thing left standing of our house is the two chimneys,” resident Darren Kettle told the newspaper. “My heart dropped to my stomach. It’s just shocking, traumatic.”

Climate scientists say warming temperatures have created wet winters that allowed California’s coastal chaparral — areas dominated by small trees, shrubs and bushes — to thrive. Record-high temperatures this summer dried out hillsides, priming them for wildfire.

The United States is experiencing a strong wildfire year with 8.1 million acres (3.3 million hectares) burned to date, compared with an annual, full-year average of around 7 million acres over the last decade, according to National Interagency Fire Center data.

So far this year, California wildfires have burned more than three times as much land as last year at this time last year, according to Cal Fire data.