Fueled by strong winds, the growing Hawk fire spread from the Sierra foothills, threatening Reno’s northwest flank on Sunday and forcing thousands of evacuations..

By 1 p.m. Sunday, the blaze had covered 13,000 acres, with 0% containment, in the area north of Lake Tahoe on the California-Nevada border. The flames’ advance spurred local evacuation orders and establishment of several evacuation centers in Reno, including the Reno-Sparks Convention Center.

Shane Ackerson, one of three unified incident commanders working the Hawk fire, said at a Sunday news conference that six people had been injured, including three first responders.

Nearly 42,000 people had been evacuated, and several structures had burned.

Ackerson said about 5,000 homes and businesses in the area were without power, and that another 45,000 people were prepared to evacuate. Ackerson said about 800 firefighters are working on the fire, including local, state and federal agencies.

Cal Fire was among the agencies sending resources to fight the Hawk fire, a spokesperson said.

Fire evacuation warning zones had reached within 1,000 feet of the University of Nevada, Reno campus, where 24,000 students were due to begin fall classes on Monday.

The fire’s cause was listed as “human,” with no further details immediately available, officials said.

Firefighting efforts in Reno and the Peavine Mountain foothills included three helicopters flying Saturday night. On Sunday, bulldozers worked on the south and east portions of the fire to create a firebreak between the blaze and residential areas.

Multiple air tankers worked on the western edge of the flames. In a statement, the Truckee district said the fire was “fueled by strong, gusty winds, low humidity and dry vegetation.”

“We expect those same strong winds to come back this afternoon,” said Chief Richard Edwards of the Reno-based Truckee Meadows Fire Protection District at a Sunday news conference.

The Washoe County Sheriff’s Office reported that portions of U.S. Route 395 had been closed.

Nevada Gov. Joe Lombardo declared a state of emergency in Washoe County late Saturday, saying that the fire “is spreading quickly and threatening homes and structures.” Reno Mayor Hillary Schieve urged residents to comply with evacuation orders, adding that “structures have already been burned in this fire and your life is worth more than a building.”

A 92-degree high was expected in Reno on Sunday. As of noon Sunday, Reno-Stead Airport, just north of the blaze, had been closed to all but firefighting and military aircraft. The busier Reno-Tahoe International Airport remained open.

The Hawk fire is part of a busy fire season in the region. Over the last two weeks, crews have been battling the Bug fire, which began Aug. 10 and had burned 93,733 acres, more than 12,000 of them in California, and was 94% contained on Sunday morning, according to Watch Duty. The nearby Stallion fire, which began Aug. 11, had burned 40,691 acres and was 98% contained. The Bug, Stallion and Hawk fires are all within about 50 miles of each other.

The Associated Press contributed to this report.