GREENVILLE, Calif. — A 3-week-old wildfire engulfed a tiny Northern California mountain town, wiping out historic buildings and leaving much of the historic downtown and blocks of homes in ashes, while a new wind-whipped blaze also destroyed homes as crews braced for another explosive run of flames Thursday in the midst of dangerous weather.

The Dixie Fire, swollen by bone-dry vegetation and 40-mph gusts, raged through the northern Sierra Nevada community of Greenville on Wednesday evening. A gas station, hotel and bar were among many fixtures gutted in the town, which dates to California’s Gold Rush era and had some structures more than a century old.

The fire “burnt down our entire downtown. Our historical buildings, families’ homes, small businesses, and our children’s schools are completely lost,” Plumas County Supervisor Kevin Goss wrote on Facebook.

Officials could not immediately say how many buildings were razed, but photos and video from the scene indicate the destruction was widespread.

“We lost Greenville tonight,” U.S. Rep. Doug LaMalfa, who represents the area, said in an emotional Facebook video. “There’s just no words.”

As the fire’s north and eastern sides exploded Wednesday, the Plumas County Sheriff’s Office issued a warning online to the town’s approximately 800 residents: “You are in imminent danger and you MUST leave now!”

The growing blaze that broke out July 21 is the state’s largest current wildfire and had blackened over 504 square miles, territory larger than the city of Los Angeles.

By Thursday, it had become the sixth-largest fire in state history, the California Department of Forestry and Fire Protection said. Four of the state’s other five largest wildfires were all in 2020.

Neighboring Lassen Volcanic National Park was closed to all visitors because of the fire.

There were no immediate reports of injuries or deaths. Dozens of homes had already burned before the flames made a new run on Wednesday.

“We did everything we could,” fire spokesman Mitch Matlow said. “Sometimes it’s just not enough.”

About 100 miles to the south, officials said between 35 and 40 homes and other structures burned in the fast-moving River Fire that broke out Wednesday near Colfax, a town of about 2,000 residents. Within hours it ripped through nearly 4 square miles of dry brush and trees.

There was no containment and about 6,000 people were under evacuation orders across Placer and Nevada counties, according to the California Department of Forestry and Fire Protection.

Early in the week, some 5,000 firefighters had made progress on the Dixie Fire, saving some threatened homes, bulldozing pockets of unburned vegetation and managing to surround a third of the perimeter.

More fire engines and bulldozers were being ordered to bolster the fight, Matlow said. On Wednesday, the fire grew by thousands of acres and an additional 4,000 people were ordered to evacuate, bringing nearly 26,500 people in several counties under evacuation orders, he said.

Red flag weather conditions of high heat, low humidity and gusty afternoon and evening winds erupted Wednesday and were expected to be a continued threat.

The trees, grass and brush were so dry that “if an ember lands, you’re virtually guaranteed to start a new fire,” Matlow said.

The Dixie Fire was running parallel to a canyon area that served as a chimney, making it so hot that it created enormous pyrocumulus columns of smoke. These clouds bring chaotic winds, making a fire “critically erratic” so it’s hard to predict the direction of growth, he added.

Dawn Garofalo fled with a dog and two horses from a friend’s mountain property, and watched the soaring cloud grow from the west side of Lake Almanor, a popular summer resort area with boating, fishing and camping.

“There’s only one way in and one way out,” she said Wednesday. “I didn’t want to be stuck up there if the fire came through.”

In Colfax, resident Jamie Brown ate breakfast Thursday morning in a downtown restaurant while waiting to learn if his house was still standing or not.

He evacuated his property near Rollins Lake on Wednesday when “it looked like the whole town was going to burn down.” Conditions had calmed a bit by Thursday and he was hoping for the best.

“I figure I better have a nice breakfast before I lose my home,” he said. “My house is right in the way if the wind puts the fire on a separate path.”