Redding, Calif. • Fueled by an incendiary combination of scorching temperatures, dry air and unpredictable winds, the deadly Carr Fire has doubled in size to 80,906 acres - almost the size of the city of Philadelphia. The wildfire has forced thousands to flee, torched 500 buildings and killed two firefighters trying to contain it.

Fire Inspector Jeremy Stoke was killed battling the Northern California blaze, the Redding Fire Department announced. The other firefighter, a privately hired bulldozer operator, has yet to be publicly identified.

The deaths underscored the hazards of a blaze that Cal Fire Chief Brett Gouvea called "extremely dangerous and moving with no regard to what's in its path."

The National Weather Service issued a red flag warning on Friday, saying fire-favorable conditions would exist until at least 8 a.m. Monday. The fire was so strong it was producing wind gusts of up to 50 mph and fire whirlwinds — tornado-like funnels of fire, ash and combustible gas. Smoke from the Carr Fire could be seen from space.

Authorities say the fire started on Monday, when a car having some sort of mechanical issue sparked a spreading blaze.

But that slow burn "became very active" later in the week as weather conditions tilted in the fire's favor, Gouvea said.

On Thursday morning, it was burning across 20,000 acres, fire officials said. Within 24 hours, it had doubled in size, thwarting efforts to bring it under control.

By Saturday morning, only 5 percent of the fire was contained.

Gov. Jerry Brown has declared a state of emergency in Shasta County, where Redding sits about two hours south of Oregon, and in other counties where the state battled multiple raging fires.

As the Carr Fire’s flames beelined toward populated areas, emergency management officials scrambled to get thousands to safety — and to protect the property they left behind.

Marin County reported that three of its firefighters working on defending structures were burned on their ears, face and hands by a sudden, scorching blast of heat. All three were released from the hospital, with one expected to receive an additional evaluation. Gouvea also said civilians had been injured, although authorities did not immediately provide further details.

Although the death toll remains at two, there are still an untallied number of people who authorities fear may have been unable to escape the fire.

Before the blaze engulfed a home on Quartz Hill Road, Melody Bledsoe and her great-grandchildren Emily and James Roberts called loved ones in a panic, saying they could see the flames.

"She was screaming, "It's getting closer," and you could hear the sirens," Donald Kewley, the boyfriend of Bledsoe's granddaughter, told the San Francisco Chronicle. "Then the phone went dead."

When they returned to the home after the flames had passed, "the whole neighborhood is gone," he told the newspaper. "It's absolutely obliterated. It's just a smoldering mess."

Ed Bledsoe, Melody's husband, has been searching evacuation shelters after cadaver dogs that went over the burned remains of his home came up with nothing.

"I just don't see how I can go without them," he told CBS News. "Somebody has to know where they're at."

The weather was counteracting firefighters' efforts to make a dent in the blaze. Forecasts for the weekend said temperatures could approach 110 degrees on Saturday and Sunday, the Weather Service said. The humidity hovered around 5 to 10 percent, and winds gusted to 30 mph in some canyons that were on fire.

The result, warned the National Weather Service: "Dangerous and rapid irregular spreading of a large wildfire threatening life and property."

For people in affected or threatened areas, the message was simple: Leave. But even people spreading that message were threatened by the quickly-expanding fire.

Power went out at the Record Searchlight newspaper in Redding, while ABC affiliate KRCR had to stop its broadcast to evacuate its offices.

Residents described a sense of confusion as the fire continued to burn closer. Amber Bollman said she and her husband, Tim, received mandatory evacuation notices at their home near the Sacramento River — followed by notices saying they did not have to leave their home, but should be prepared to do so.

"We have about 10 firefighters who live in the neighborhood and they were saying as long as it didn't jump the river, we'd be safe," Bollman said. "We know [the fire personnel] were doing their best, but there was definitely a lack of communication about how rapidly it was coming."

They packed up some of their things and headed east to her parent's house in Shingletown. Tim Bollman and his 14-year-old son, Jack, went back for more. With Jack recording video, they followed fire personnel out of their neighborhood and saw flames surrounding the truck as they left, she said.

"They barely made it out," she said.

On Friday morning, Bollman said they found out that their home had been lost.

"You get as much as you can, you get out with your life, but your home is so much a part of you that you can't replace," she said. "It's material, but we have nothing. We have our lives and family and friends, but we just feel lost."

Michelle Harrington, a teacher who lives near the Bollmans, said she and her husband packed things up in their car on Thursday afternoon. They were watching the evening news after 6 p.m. when her sister texted that flames were coming over the ridge.

"We opened the garage door and it was like a hurricane; the trees were bent over and garbage cans were blowing down the street," Harrington said. "I thought we were going to die. I didn't know if we were going to get out of there."

They escaped to her parent's house on the east side of Redding. Without knowing what happened to their home, Harrington said they have begun wondering what they will do next.

"We’re already thinking long term — where do you go? How long before we have a home again?' she asked.

Complicating matters for firefighters was the fact that they were fighting a battle on multiple fronts.

The Ferguson Fire, which forced officials to close the Yosemite Valley through at least the weekend, has burned across nearly 50,000 acres since mid-July and was 29 percent contained as of Saturday morning, fire officials said.

The Cranston Fire in Riverside County had burned across 12,300 acres and was 16 percent contained, officials said.