SANTA ROSA, Calif. — It wasn’t the smoke or heat, but the sound of a honking car horn that jolted Seth Knox’s family awake at 1:30 a.m. Monday.

One of their neighbors — entrusted with a gate code — had made her way up the long driveway of the Knox’s home in Sonoma. She had been going door to door, warning friends of a wildfire headed their way.

Knox stepped outside and peered into the darkness. An orange glow appeared over the ridge, lighting up a silhouette of the mountains. Around them, a gusting wind howled through the tall pine trees on his property, blowing smoke their way.

Knox was shocked.

None of that had been even remotely apparent when he had gone to bed about 10 p.m.

“You could feel it in your eyes, and it was in your throat,” Knox told The Washington Post. “There were kind of flames whipping over the ridge.”

Instantly, they decided to leave home. Knox, his wife and two daughters threw a few days’ worth of clothes into carry-on bags and loaded their belongings — along with their barking dogs, a Labrador puppy and a cocker spaniel — into the family’s two cars. Within minutes, they were driving out of the neighborhood, stopping to knock on the doors of friends’ houses along the way.

“We didn’t take any personal items or documents or anything,” Knox said. “We just left…. We’re lucky we got out when we did.”

Knox would soon learn that similar scenes had played out across California’s wine country, where at least 17 separate fires have ravaged Northern California since Sunday, fueled by “red flag” fire conditions and 50- to 60-mph winds.

The fast-spreading fires have burned more than 107,000 acres — a collective area roughly the size of New Orleans — and killed at least 15 people, with at least 150 more still reported missing. Authorities warned Tuesday that the death toll was likely to go up.

Santa Rosa, the largest city in Sonoma County, bore severe early damage after a blaze dubbed the “Tubbs Fire” moved into the city late Sunday. The flames forced at least two hospitals in Santa Rosa to evacuate their patients and destroyed Fire Station 5.

Drone footage from Sunday showed whole neighborhoods in the city engulfed in fire.

As the Tubbs Fire approached Daniel and Cindy Pomplun’s rural Santa Rosa home late Sunday, the couple found themselves trapped on the first floor. There had been no warning — just the sight of the flames, they would recall later.

“We got lower and lower until we were down to a foot,” Daniel Pomplun, 54, told The Post on Tuesday from an evacuation center in nearby Windsor, Calif.

As smoke filled their home, they ran outside and jumped into their pool in the middle of the night.

It was a startling contrast: Despite the encroaching blaze, the air temperature had dipped into the 40s overnight, and the water was unbearably cold. Mostly submerged, the couple shivered from the shoulders down and felt blistering heat from the neck up.

For an hour and a half, the Pompluns waited in the pool as the fire engulfed their home and the acreage around it. They periodically ducked underwater to avoid the smoke, emerging to breathe with washcloths draped over the backs of their heads.

When the fire passed, the Pompluns lay shivering on the hot stones of their patio, taking off one item of clothing at a time to let the heat from the stones dry them.

At that point, they said, their only option was to leave the neighborhood on foot. On their way out, the couple “broke in,” as they put it, to a neighbor’s house to pick up more shoes and clothes. Within a mile and a half of their trek, a Sonoma County sheriff’s deputy spotted them and drove them to an evacuation center.

At the time, one Santa Rosa resident compared the evacuation scenes to something “like Armageddon.”

“People are running red lights,” Ron Dodds told KTVU. “There is chaos ensuing.”

Even by the standards of a severe wildfire season in the West, the rapid spread of the Northern California fires was shocking — “a phenomenal rate of growth,” Cal Fire spokesman Jonathan Cox said. Officials began ordering mandatory evacuations about 11 p.m. Sunday, forcing thousands of residents to flee their homes and schools to close across the region.

The smoke from the wine-country fires was so severe that many in San Francisco, more than 40 miles to the south, reported being able to smell it.

“This is really serious. It’s moving fast,” California Gov. Jerry Brown (D) said at a news conference Monday. “The heat, the lack of humidity and the winds are all driving a very dangerous situation and making it worse. It’s not under control by any means. But we’re on it in the best way we know how.”

In Napa and Sonoma counties alone, hundreds of homes had been “catastrophically destroyed,” Brown wrote Monday in a lengthy letter to the White House seeking federal assistance as he declared a state of emergency in seven counties.

In Rincon Valley, on the northeastern outskirts of Santa Rosa, Pastor Andy VomSteeg opened his New Vintage Church to those fleeing the fire.

By Monday afternoon, more than 400 people, many of them elderly, had taken refuge inside.

“I left without my clothes,” said Nell Magnuson, a resident of the luxury retirement home Villa Capri. She wore only a maroon robe.

“We had to get out in a hurry,” she said. “When we left, the flames were in the second floor.”

Magnuson, who was worried about where she would sleep Monday night, said that “our whole lives have turned upside down. We don’t have a clue what’s going to happen. It’s just losing everything. All the pictures, my whole life.”

But before her concerns could be addressed, the fire began to threaten the church.

“You caught us just in time,” Magnuson said as she headed for the exit. “We’re being evacuated again.”

Aerial pictures of Santa Rosa showed street after street of homes burned to the ground, smoke still twisting between the charred remains of pine trees.

Post-apocalyptic images emerged from a destination typically known for its breathtaking hillsides and picturesque vineyards.

Washington state residents Chris Thomas and his wife, Marissa Schneider, told the San Francisco Chronicle that they were forced to evacuate the Silverado Resort and Spa in Napa shortly after arriving there Sunday night for what was supposed to be a wine-tasting vacation.

“We were sleeping, but we kept smelling smoke,” Thomas, 42, told the newspaper.

A loudspeaker soon ordered them to leave, he added. “When I started loading stuff into the car, it was a hell-storm of smoke and ash. There were 30 to 40 mph winds. I couldn’t even breathe, so I ran back to the unit to get Marissa. It was so smoky I went to the wrong unit.

“When I found her, I said: ‘Forget it. Let’s just go.’ It went from being an annoying evacuation to something really scary.”

Fire glows on a hillside in Napa. (Josh Edelson/AFP/Getty Images)

Firefighters drive through the Coffey Park area of Santa Rosa, looking for hot spots. (Ben Margot/AP)

Smoke rises at the Journey’s End trailer park in Santa Rosa. (Paul Kitagaki Jr./Sacramento Bee via AP)

Donosky reported from Windsor, Calif., Wang from Washington. This post has been updated.

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