A wildfire that has tripled in size in one day, becoming California’s largest of the year even as other blazes scorched the Pacific Northwest, was started by a burning car, authorities said. They arrested a man who was seen pushing the blazing car into a gully.

The man was seen pushing the car in Bidwell Park in Northern California’s Butte County, and it burned completely, spreading flames that caused the Park Fire, county prosecutor Mike Ramsey said in a news release. The blaze had burned more than 257 square miles (666 square kilometers) by early Friday near Chico, a city of about 100,000.

The man calmly left the area, in one of the nation’s largest urban parks, by blending in with other people and fleeing the “rapidly evolving fire,” officials said. The 42-year-old man from Chico was arrested early Thursday and being held without bail until an arraignment hearing Monday, officials said.

Evacuations were ordered in Butte and Tehama counties, with the blaze only 3% contained by Friday morning. About 4,000 residents in unincorporated areas of Butte County and 400 residents of Chico were ordered to evacuate, Butte County Sheriff Kory Honea said at a news conference late Thursday.

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An unspecified number of structures have been destroyed, and two minor injuries were reported, Butte County Fire Chief Garrett Sjolund said.

“The fire quickly began to outpace our resources because of the dry fuels, the hot weather, the low humidities and the wind,” Sjolund said.

Also in California, near the Nevada line, about 1,000 people remained displaced Thursday after evacuations were ordered Monday night when lightning sparked the Gold Complex fires. The fires have burned more than 4 square miles (10 square kilometers) of brush and timber in the Plumas National Forest about 50 miles (80 kilometers) northwest of Reno, Forest Service spokesperson Adrienne Freeman said.

There have been no reports of structural damage, deaths or serious injuries, but the fires were at zero containment Thursday amid gusty winds that were also plaguing crews working the Park Fire, authorities said.

A fire in Southern California was much smaller but moving fast and threatening homes. Evacuation orders were in effect Wednesday night in northern San Diego County. The Grove Fire was 10% contained by Thursday afternoon. Some residents were under evacuation orders.

As evacuations continued in California, some Oregon residents were cleared to return home after a thunderstorm produced welcome rain but also potentially dangerous lightning over the biggest active blaze in the United States.

Evacuation orders were lifted for the eastern Oregon city of Huntington, population 500, after a thunderstorm late Wednesday brought some rain and cooler temperatures to the nearly 630 square miles (1,630 square kilometers) burned by the Durkee Fire, the nation’s biggest, and another nearby blaze.

Baker County Sheriff Travis Ash called the rain a “godsend,” and the Oregon state fire marshal said firefighters were set to “seize the opportunity” of better conditions to push back the fire on the Oregon-Idaho border. It remained unpredictable and was just 20% contained, according to the government website InciWeb.

Lightning strikes started 15 new fires overnight in Idaho, the U.S. Forest Service told Boise’s KBOI-TV, but several had already been extinguished by Thursday afternoon.

More than two dozen new fires started in Montana on Wednesday and early Thursday. And in the Canadian Rockies’ Jasper National Park, a fast-moving wildfire this week hit the park’s namesake town, forcing thousands to flee and causing significant damage in the World Heritage Site. That blaze, like those in the Western United States, led to some air quality alerts or advisories as skies filled with smoke and haze.

Overall, more than 1,500 square miles (more than 4,000 square kilometers) have burned so far this summer in the Pacific Northwest. Oregon alone has over 30 large fires, almost all of them in the central or eastern part of the state.

Climate change is increasing the frequency of wildfires sparked by lightning across the Pacific Northwest and western Canada as the region endures recording-breaking heat, with many triple-digit days and bone-dry conditions. Idaho Power has for the first time instituted a pre-emptive power outage, shutting off electricity to thousands of customers to prevent new fire starts and other power grid issues from wires downed by the high winds, the utility said.

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Associated Press writers Sarah Brumfield, Claire Rush, Scott Sonner, Martha Bellisle and Amy Hanson contributed to this report.