PHOENIX — A new wildfire that erupted on the slopes outside Yarnell — scene of the 2013 disaster that killed 19 firefighters — sent at least 250 residents scrambling to evacuate and fire crews racing to block the flames from town.

Dubbed the Tenderfoot Fire, the blaze was burning on a hill east of State Route 89, according to Yavapai County Sheriff’s Deputy Dwight D’Evelyn. It had destroyed at least one structure —- a shed — and several cellphone towers, according to officials.

Several air tankers were on the scene before dark, with at least one dropping a line of orange fire retardant as a barrier between the fire and structures closer to State Route 89. Later, officials would credit the slurry drops for removing any fire threat to property.

The highway was closed between Yarnell and Peeples Valley, according to the Arizona Department of Transportation.

D’Evelyn said the blaze had scorched 600 to 700 acres by 8:45 p.m.

Parts of the fire had laid down by dusk, but officials continued to be concerned about fire activity and were leading evacuations, D’Evelyn said. Deputies were focusing on residents with disabilities, and ambulances had made several runs to assist them he said.

Evacuations stopped as of 8:30 p.m. D’Evelyn said fire incident commanders felt it was safe for residents to stay, although roadblocks on both sides of town would stay in place overnight. Officials will re-evaluate evacuation plans in the morning, he said.

Local fire agencies, along with the Bureau of Land Management, were responding to the fire.

“This is priority one right now — the top priority in the state,” Dolores Garcia, a wildfire spokeswoman for the BLM, said earlier in the day.

Garcia said the fire was less than a mile southeast of Yarnell and had moved rapidly. She said it had been pushed by winds up to 15 mph, and was burning through a chaparral area that was not consumed during the fatal blaze of 2013.

The fire appeared to move northeast, burning up-slope just east and away from the town, on the opposite side of SR 89. A photo showed flames moving up Y Mountain, just beyond a monument that was established in honor of the firefighters who died in 2013.

By nightfall, the fire had reached the top of that ridge, destroying cell towers there, D’Evelyn said.

Garcia said aircraft, ground crews and engines were moving to attack the fire. That included firefighters from Yarnell, Congress, Peeples Valley, the BLM and the U.S. Forest Service. Fire administrators reported that a heavy air tanker, two single-engine air tankers and a trio of elite “type-1″ wildland fire crews were ordered to the blaze early Wednesday evening.

Garcia said conditions in central Arizona are extremely dry with a high fire danger.

The last measurable rainfall in the area was in Prescott at .04 inches on May 17, and “traces” of rain on May 18. The highest temperature was 69 degrees both days. National Weather Service meteorologist Hector Vasquez said the area has seen warmer temperatures since then and high winds in the afternoon, drying up plants into the summer.

“The vegetation has gotten dryer,” Vasquez said. “That’s why it’s fire season. Everything is bone dry. Any moisture that fell in the spring is gone by now until the July monsoon season.”

Garcia said the cause of the fire was under investigation, but she noted there was no lightning in the area Wednesday.

Yarnell resident Vanessa Purdy said she noticed smoke from the fire about 3:30 p.m. Wednesday and then received a voluntary evacuation notice on her cellphone.

Purdy lost her home and a neighboring rental home in the Yarnell Hill Fire in 2013.

She scrambled to pack up her belongings Wednesday afternoon as she spoke to The Arizona Republic on the telephone.

“I’m a little smarter on what to grab” this time, she said. “I’m just shivering on the inside. There’s definitely some lingering PTSD from the last time.”

Purdy said she received a text alert from the Sheriff’s Office at 6:02 p.m. that said “west of Yarnell under mandatory evacs. Report to Yavapai College.”

American Red Cross volunteers were expected to open an evacuation center by 6 p.m. at Yavapai College in Prescott.

Arizona Public Service reported that more than 1,000 customers in Yarnell were without power Wednesday evening.

“We’ve been told to evacuate. It’s horrific,” said Yarnell resident Jerry Florman over the telephone as he left town. “I’m halfway down the mountain with the dog.”

“I’m guessing there will be plenty of people saying I’m not going to go back. It’s so hard.”

Florman and her husband, Kurt, lost their home in the 2013 fire and have since purchased another home in town.

Yarnell was the scene of one of the deadliest wildfires in history.

On June 28, 2013, a lightning storm ignited the Yarnell Hill Fire in the high desert northwest of Phoenix. Two days later, the brush fire that covered a few hundred acres exploded across 13 square miles.

Hundreds of people fled from Yarnell, Glen-Ilah and Peeples Valley as flames destroyed 127 homes.

The Granite Mountain Hotshots, who had been hand-cutting firebreaks along the blaze’s flank, descended from a mountain ridge into a bowl where they became trapped. The 19 men deployed protective shelters, but all were overcome by a wall of fire so hot it fractured boulders.

Memorials for the fallen firefighters played out for months, and questions about what went wrong that day have lingered in the years since.

Chuck Overmyer watched the fire burn from his home in Glen Ilah, a subdivision across the highway from Yarnell that was devastated by the 2013 Yarnell Hill Fire.

Overmyer and his wife, Nina Bill, lost their home and nearly all of their possessions in that blaze and had to rebuild.

“It’s horrible,” he said Wednesday evening in a telephone interview as he watched a helicopter drop water on the blaze and juggled a steady stream of calls to his cellphone.

He said he has no plans to evacuate and didn’t feel in danger at the moment.

“If it comes this way, I’m going to grab the garden hose. I’m going down with the house this time.”

Contributing: Lindsey Collom, Adrian Hedden and Alexis Egeland, The Arizona Republic. Follow Ricardo CanoAnne Ryman and Dennis Wagner on Twitter: @Ricardo_Cano1@anneryman and @azrover