SHAVER LAKE, Calif. >> Evacuation orders were expanded today to more mountain communities as a huge wildfire churned through California’s Sierra National Forest, one of dozens of blazes crews battled during a heat wave that shattered records across the state.

Firefighters working in steep terrain through the night saved the tiny town of Shaver Lake from flames that roared down hillsides toward a marina. To the north, about 30 houses were destroyed in the remote hamlet of Big Creek.

“About half the private homes in town burned down,” Big Creek resident Toby Wait said. “Words cannot even begin to describe the devastation of this community. And it is a very close-knit community.”

An elementary school, church, library, historic general store and a major hydroelectric plant were spared in the community of about 200 residents, Wait told the Fresno Bee.

Sheriff’s deputies went door to door to make sure residents were complying with orders to leave. Officials hoped to keep the fire from pushing west into rural towns along State Route 41 and possibly Yosemite National Park.

The blaze dubbed the Creek Fire has charred more than 114 square miles of timber after breaking out Friday. The 850 firefighters on the scene had yet to get any containment after three days of work in sweltering heat. There was no official tabulation yet of structures lost.

On Saturday, rescuers in military helicopters airlifted 207 people to safety after flames trapped them in a wooded camping area near Mammoth Pool Reservoir northeast of Fresno.

In Southern California, crews scrambled to douse several fires that roared to life in searing temperatures, including one that closed mountain roads in Angeles National Forest. The California Department of Forestry and Fire Protection, or Cal Fire, said a blaze in San Bernardino County called the El Dorado Fire started Saturday morning and was caused by a smoke-generating pyrotechnic device used by a couple to reveal their baby’s gender.

A fire in the Angeles National Forest northeast of Los Angeles forced the evacuation of Mount Wilson Observatory.

In eastern San Diego County, the Valley Fire broke had destroyed at least 10 structures after burning 16 square miles and prompting evacuations near the remote community of Alpine in the Cleveland National Forest.

Daytime temperatures in fire zones neared or exceeded triple digits. Downtown Los Angeles reached 111 degrees on Sunday and a record-shattering high of 121 degrees was recorded in the nearby Woodland Hills neighborhood of the San Fernando Valley. It was the highest temperature ever recorded in Los Angeles County, according to the National Weather Service.

Meanwhile, downtown San Francisco set a record for the day with a high of 100 on Sunday, smashing the previous mark by 5 degrees.

The exceptionally hot temperatures were driving the highest power use of the year, and transmission losses because of wildfires have cut into supplies. The California Independent System Operator that manages the state’s power grid warned that up to 3 million people could lose power Sunday if the if residents didn’t curtail their electricity usage.

About 7 p.m., the agency declared an emergency and said power outages were imminent because a transmission line carrying power from Oregon to California and another in-state power plant went offline unexpectedly. But about 8:30 p.m., the agency issued a tweet calling off the emergency “thanks to conservation of Californians!.” It said no power outages were ordered.

The weather forecast called for more heat today and the grid operators again urged people to conserve power between 3 p.m. and 9 p.m.. when usage is highest. Cooler temperatures were expected Tuesday but the weather change also was expected to bring winds that could fan wildfires.

Pacific Gas & Electric, the state’s largest utility serving customers in Central and Northern California, warned customers that it might cut power starting Tuesday because of the increased fire danger. Some of the state’s largest and deadliest fires in recent years have been sparked by downed power lines and other utility equipment. All of Northern California has moderate to severe drought conditions.

Cal Fire said 14,800 firefighters were battling 23 major fires in the state. California has seen 900 wildfires since Aug. 15, many of them started by an intense series of thousands of lightning strikes. The blazes have burned more than 2,343 square miles. There have been eight fire deaths and more than 3,300 structures destroyed.