OROVILLE, Calif. (AP) — A Northern California wildfire threatened thousands of homes Thursday after winds whipped it into a monster that incinerated houses in a small mountain community and killed at least three people.

Several other people have been critically burned and hundreds, if not thousands, of homes and other buildings are believed to have been damaged or destroyed by the North Complex fire northeast of San Francisco, authorities said.

Some 20,000 people were under evacuation orders or warnings in Plumas, Yuba and Butte counties.

Between Tuesday and Wednesday, the fire — which had been burning for weeks in forestland and was 50% contained — exploded to six times its size as winds gusting to 45 mph drove a path of destruction through mountainous terrain and parched foothills.

The winds subsided Wednesday but the fire was only 24% contained and the danger remained.

“Time and time again we have seen how dangerous wildfires can be. … So I ask that you please, please please be prepared, maintain situational awareness and heed the warnings,” Butte County Sheriff Kory Honea pleaded.

Honea announced the three deaths but declined to provide details. California Highway Patrol Officer Ben Draper told the Bay Area News Group that one person was found in a car and apparently had been trying to escape the flames.

Many homes were incinerated in the Butte County hamlet of Berry Creek, with a population of 525 people.

John Sykes, a 50-year resident, managed to flee on Tuesday with his car and some clothes but he watched the town burn from about a mile away.

“The school is gone, the fire department’s gone, the bar’s gone, the laundromat’s gone, the general store’s gone,” he told the Sacramento Bee, adding, “I’ll never go back.”

“I don’t want to see it,” he said. “That’s why I’m leaving. I never want to see California again.”

Four burn victims were taken to UC Davis Medical Center in critical condition, the Bee reported.

The fire also threatened Paradise, a town devastated just two years ago by the deadliest blaze in state history that prompted a deadly traffic jam as panicked residents tried to escape. Eighty-five people lost their lives and nearly 19,000 buildings were destroyed in that fire.

On Wednesday, the sky turned from black to cherry red and ash carried on strong winds rained down in a scene reminiscent from the fateful morning of Nov. 8, 2018, former Mayor Steve “Woody” Culleton said.

“It was extremely frightening and ugly,” Culleton said. “Everybody has PTSD and what not, so it triggered everybody and caused terror and panic.”

Even in the midst of its dry, hot, windy fire season, California has seen wildfires advancing with unprecedented speed and ferocity. Since the middle of August, fires in California have killed 11 people, destroyed more than 3,600 structures, burned old growth redwoods, charred chaparral and forced evacuations in communities near the coast, in wine country and along the Sierra Nevada.

Thick smoke choked much of the state and cast an eerie orange hue across the sky. In some areas of the San Francisco Bay Area and the Sacramento Valley, the smoke blocked out so much sunlight that it dropped the temperature by 20 to 30 degrees over the previous day, according to the National Weather Service.

More than two dozen major fires were burning around the state, some of them among the largest ever recorded in recent California history.

The U.S. Forest Service, which had taken the unprecedented measure of closing eight national forests in Southern California earlier in the week, ordered all 18 of its forests in the state closed Wednesday for public safety.

In Southern California, fires burned in Los Angeles, San Bernardino and San Diego counties. People in foothill communities east of Los Angeles were warned to be ready to flee, but the region’s notorious Santa Ana winds were weaker than predicted.

“We’re encouraged that the wind activity appears to be dying down,” Gov. Gavin Newsom said. “The rest of the week looks a little more favorable.”

Melley reported from Los Angeles. Associated Press writers John Antczak in Los Angeles and Olga R. Rodriguez in San Francisco contributed to this report.