Thousands of firefighters continued to battle the Park fire in northern California which, propelled by extreme fire weather conditions, has become the state’s seventh-largest on record after burning for less than a week. The Park fire, about 90 miles (144km) north of the state capital of Sacramento, had more than doubled in size in a 24-hour span to burn upwards of 350,000 acres (141640 hectares) – an area about the size of Los Angeles – and stretched over four counties: Butte, Plumas, Shasta and Tehama, according to the California department of forestry and fire protection, or Cal Fire. “This fire is surprising a lot of people with its explosive growth,” said Jay Tracy, a spokesperson at the Park fire headquarters. “It is kind of unparalleled.” Cooler temperatures and more humid air were expected in the region, potentially helping efforts to slow the spread of the fire, which was 12% contained as of Sunday morning. Authorities had reassessed the damage the blaze has caused and reported that 66 structures have been destroyed and thousands more remain under threat; however no deaths have been reported. “Unfortunately, that number will probably go up,” Tracy said. “Each day that number has potential to grow – our teams obviously don’t do damage inspections when there is active fire in an area.” The Park fire’s intensity and rapid spread led fire officials to make unwelcome comparisons to the disastrous Camp fire in 2018, which burned out of control in nearby Paradise, killing 85 people and destroying 11,000 homes and became the deadliest fire in California’s history. Paradise was once again under evacuation orders as were several other communities in each of the four counties. Jeremy Pierce, Cal Fire operations section chief, had some good news for the area, saying around midday that the Park fire’s southernmost front, which is closest to Paradise, was “looking really good”, with crews focusing on mopping up the area over the next three days. He also said they don’t expect it to move farther into Chico, a city of about 100,000 people just west of Paradise. Joe Biden has been briefed on the fire and has directed his team to do everything possible to support efforts to fight it, a White House official said. Gavin Newsom made an emergency declaration for the counties of Plumas, Butte and Tehama as thousands of residents were fleeing their homes. “We are using every available tool to protect lives and property as our fire and emergency response teams work around the clock to combat these challenging fires,” the California governor said in a statement. More than 110 active fires covering 2,800 sq miles (7,250 sq km) were burning in the US on Friday, according to the National Interagency Fire Center. Some were caused by the weather, with the climate crisis increasing the frequency of lightning strikes as the region endures record heat and bone-dry conditions. The Park fire was caused by arson after authorities say a man identified as Ronnie Dean Stout was seen pushing a burning car into a ravine near Chico on Wednesday, according to the Sacramento Bee. Police said they arrested him Thursday after he fled the scene with others as the fire spread. Stout remained in the Butte county jail on Saturday and was scheduled to be arraigned on Monday. The fire was the largest of dozens of active blazes across the country that have burned more than 2m acres, according to the National Interagency Fire Center. In Oregon, several fires were burning, including the Durkee fire, which had scorched more than 288,000 acres in the eastern part of the state, authorities said. A firefighter died after a single-engine tanker crashed near the Falls fire in south-eastern Oregon, the US Forest Service said in a statement on Friday.