Trabuco Canyon, California (AP) — A man was arrested Tuesday on suspicion of arson after three massive wildfires in California sent apocalyptic plumes of smoke into the air east of Los Angeles during a scorching heat wave, threatening tens of thousands of homes and other buildings.

Evacuation orders were expanded Tuesday night as the fires grew to include parts of the popular ski town of Big Bear and the entire community of Wrightwood, home to about 4,500 people. Authorities urged people to leave their homes.

“There is no property worth risking your life for,” said Los Angeles County Sheriff Robert Luna.

In recent years, wildfires have raged regularly in and around Wrightwood, a picturesque mountain town 60 miles east of Los Angeles known for its 1930s cabins. Authorities expressed frustration in 2016 when only half of residents heeded orders to leave.

Janice Quick, president of the Wrightwood Chamber of Commerce, said a friend texted her to say her house had burned down, while another friend watched on her Ring camera as flames descended on her home.

Quick said she was having lunch outside with friends late in the afternoon when they were pelted with glowing coals the size of her thumbnail that fell on the table and made a clanging sound.

“I’ve never seen anything like this and I’ve been through fires before,” said Quick, who has lived in Wrightwood for 45 years.

Meanwhile, in the San Bernardino National Forest, some 65,600 homes and buildings were threatened by the Line Fire, including those under mandatory evacuation orders and those under evacuation warnings. That’s nearly double the number from the previous day.

Residents along the southern edge of Big Bear Lake were told to leave the area Tuesday night, according to the San Bernardino County Sheriff’s Department. It’s unclear how many people were affected in the area, which is a popular destination for fishermen, bikers and hikers.

Justin Wayne Halstenberg, 34, was arrested Tuesday on three arson charges in connection with the Line Fire, including arson of structures or forest land, according to the sheriff’s department and jail records. Halstenberg is being held on $80,000 bail, the sheriff’s department said. It’s unclear whether he has retained an attorney.

The fire had burned more than 51 square miles of grass and brush, blanketing the area in a thick cloud of dark smoke. The acrid air caused several districts in the area to close schools through the end of the week due to safety concerns. Three firefighters have been injured since the fire was reported Thursday, state fire officials said.

In Orange County, firefighters used bulldozers, helicopters and planes to battle a fast-moving blaze, the Airport Fire, that began Monday and spread to about 3 square miles in just a few hours. The fire was sparked by a spark from heavy equipment being used by government workers, officials said.

By Tuesday evening, it had charred more than 30 square miles and was moving across mountainous terrain into neighboring Riverside County without containment, said Capt. Steve Concialdi of the Orange County Fire Authority. It burned several communications towers on one peak, though officials said so far they had no reports of damage that would disrupt police or fire communications in the area.

Concialdi said the fire was contained outside of homes in Orange County, but there are 36 recreational cabins in the area. He said authorities do not yet know if the cabins were damaged or destroyed by the fire.

Two firefighters who were injured by the heat and a resident who inhaled smoke were treated in hospital and then released.

Sherri Fankhauser, her husband and daughter set up lawn chairs and watched Tuesday as helicopters dropped water on a burning hillside a few hundred yards from their home in Trabuco Canyon.

They were not evacuated, even though their street had been under a mandatory evacuation order since Monday. A neighbor did help Fankhauser’s 89-year-old mother-in-law evacuate, Fankhauser said. The flames died down last night but flared up again in the morning.

“You can see fire coming over the ridge now,” Fankhauser said Tuesday afternoon. “It’s getting a little scarier now.”

She said she trusted firefighters to get the situation under control and kept them informed.

In Northern California, a fire that burned less than a square mile and started Sunday has burned at least 30 homes and commercial buildings and destroyed 40 to 50 vehicles in Clearlake City, 110 miles north of San Francisco, officials said. About 4,000 people were forced to evacuate because of the so-called Boyles Fire, which was about 50% contained Tuesday night.

Other large fires raged in the West, including in Idaho, Oregon and Nevada, where about 20,000 people were displaced by a blaze outside Reno. The out-of-control Davis Fire burned at least one home and threatened dozens more. The fire started in Davis Creek Regional Park in the Washoe Valley and spread through heavy timber and brush, fire officials said.

A state of emergency declared Sunday for Washoe County by Nevada Gov. Joe Lombardo said about 20,000 people were evacuated from neighborhoods, businesses, parks and campgrounds.

More than 600 firefighters in the area remained on standby Tuesday but were bracing for worsening weather Wednesday, which could bring dangerously high winds and dry conditions. The National Weather Service in Reno said it was the first time in five years and only the sixth time in history that it had declared the threat an “extremely dangerous situation.”

All off-duty firefighters in the Reno area were ordered back to work on Wednesday.

“I’ve never done that in the 12 years I’ve been fire chief,” Truckee Meadows Fire Chief Charles Moore said Tuesday.

CNN’s Melissa Alonso contributed to this report.