Last Updated 1:55 p.m. ET
YARNELL, Ariz. Triple-digit heat and 45 mile-per-hour wind gusts fueled an out-of-control blaze Sunday in a forest northwest of Phoenix, overtaking and killing 19 members of an elite fire crew.
It was the deadliest wildfire involving firefighters in the U.S. in 80 years.
The "hotshot" firefighters were forced to deploy their emergency fire shelters -- tent-like structures meant to shield firefighters from flames and heat -- when they were caught near the central Arizona town of Yarnell, state forestry spokesperson Art Morrison told The Associated Press.
The lone survivor of the firefighting crew escaped because he was moving the crew's truck when the flames roared over the men.
The fire also destroyed an estimated 200 homes, Morrison said. Dry grass near the communities of Yarnell and Glen Isla fed the fast-moving blaze, which was whipped up by wind and raced through the homes, he said.
CBS Phoenix, Ariz. Affiliate KPHO-TV reports at least eight firefighters suffered injuries and were taken to a local hospital. The extent of their injuries wasn't known.
The men were trying to help get the blaze under control when the fire suddenly shifted, taking them by surprise.
"This fire was very radical in its behavior, said Michael Reichling, a spokesman for the Arizona State Forestry Division. "The fields were very dry, the relative humidity was low, the winds were coming out of the south. It turned around on us because of the monsoon action this afternoon. They were just caught up in a very bad situation."
By late Sunday most people had evacuated from Yarnell, a town of about 700 residents about 85 miles northwest of Phoenix. No injuries or other deaths were reported.
The fire started after a lightning strike on Friday and spread to some 8,000 acres on Sunday amid triple-digit temperatures, low humidity and windy conditions, state forestry spokesperson Carrie Dennett told CBS News.
By midday Monday the fire had grown to 13 square miles, with zero containment.
On Monday morning Gov. Jan Brewer signed an order declaring a state of emergency in Yavapai County, making $200,000 of state money available to support emergency response and recovery efforts associated with the fire.
"Nineteen lives were lost," Brewer said at a press briefing Monday, calling the firefighters "brave men who gave their lives in defense of their friends, neighbors and perfect strangers."
The disaster all but wiped out the 20-member Hotshot fire crew based in Prescott, leaving the city's fire department reeling.
"We grieve for the family. We grieve for the department. We grieve for the city," Prescott Fire Chief Dan Fraijo said at a news conference Sunday evening. "We're devastated. We just lost 19 of the finest people you'll ever meet."
"Every precaution is always taken," Fraijo said. "The trouble is, sometimes it's such an erratic situation. When you have that much fuel, in those dry conditions, it becomes very unpredictable."
All 19 members were part of the Granite Mountain Hotshots, elite firefighters who often hike for miles into the wilderness with chain saws and backpacks filled with heavy gear to build lines of protection between people and fires. They remove brush, trees and anything that might burn in the direction of homes and cities.
The crew was working around Barbara Potter's property on Saturday.
"I waved at one of them and I said, 'What's up guys, is there fire in the back of the neighborhood or something?' And they said, 'No, we're looking at where we can set up a break to try and save your neighborhood,'" Potter told CBS News, choking up. "And now they're gone."
The crew killed in the blaze had worked other wildfires in recent weeks in New Mexico and Arizona, Fraijo said.
"By the time they got there, it was moving very quickly," he told the AP of Sunday's fire.
He added that the firefighters had to deploy the emergency shelters when "something drastic" occurred.
"One of the last fail-safe methods that a firefighter can do under those conditions is literally to dig as much as they can down and cover themselves with a protective -- kinda looks like a foil type -- fire-resistant material -- with the desire, the hope at least, is that the fire will burn over the top of them and they can survive it," Fraijo said.
"Under certain conditions, there's usually only sometimes a 50 percent chance that they survive," he said. "It's an extreme measure that's taken under the absolute worst conditions."
Nineteen fire shelters were deployed, and some of the firefighters were found inside them, while others were outside the shelters, Reichling told the Arizona Republic.
The National Fire Protection Association had previously listed the deadliest wildland fire involving firefighters as the 1994 Storm King Fire near Glenwood Springs, Colo., which killed 14 firefighters who were overtaken by a sudden explosion of flames. The association website lists the last wildland fire to kill more firefighters as the 1933 Griffith Park fire in Los Angeles, which killed 29. The most firefighters - 340 - were killed in the 9/11 terrorist attacks in New York, according to the website.
U.S. wildfire disasters date back more than two centuries and include tragedies like the 1949 Mann Gulch fire near Helena, Mont., that killed 13 (recounted in Norman Maclean's award-winning 1992 book, "Young Men and Fire"), or the Rattlesnake blaze four years later that claimed 15 firefighters in Southern California.
President Obama expressed his condolences to the families of the 19 firefighters in a statement issued in Africa, where his trip continued Monday, calling the firefighters heroes and highly skilled professionals who "put themselves in harm's way to protect the lives and property of fellow citizens they would never meet." He said the federal government was assisting state and local officials.
"This is as dark a day as I can remember," Gov. Jan Brewer said in a statement. "It may be days or longer before an investigation reveals how this tragedy occurred, but the essence we already know in our hearts: fighting fires is dangerous work."
Brewer said she would travel to the area Monday.
In a statement, Sen. John McCain called the "devastating loss" "a reminder of the grave risks our firefighters take every day on our behalf in Arizona and in communities across this nation. Their sacrifice will never be forgotten."
U.S. Rep. Paul Gosar, whose district includes Yarnell, shot off a series of tweets Sunday night sending his condolences to those affected. He said his office will remain in contact with emergency responders and would offer help to those who needed it.
Other high-profile Arizonans expressed their shock on Twitter, including former U.S. Rep. Gabrielle Giffords who called it "absolutely devastating news." U.S. Sen. Jeff Flake, R-Ariz., tweeted that he was "sick with the news."
Chuck Overmyer and his wife, Ninabill, said they lost their 1,800-square-foot home in the fire.
They were helping friends flee when it switched directions and moved toward his property. They loaded up what belongings they could, including three dogs and a 1930 model hot rod on a trailer. As he looked out his rear view mirror, he could see embers on the roof of his garage.
"We knew it was gone," he said.
He later gathered at the Arrowhead Bar and Grill in nearby Congress along with locals and watched on TV as he saw the fire destroy his house.
"That was when we knew it was really gone," he said.
He later fielded a phone call from a friend in which he said, "Lost it all, man. Yep, it's all gone."
Morrison said the fire grew in intensity when winds began gusting at up to 24 mph in the late afternoon.
"You get some winds, and it can take off on you," he said.
Two hundred firefighters were working on the fire Sunday, but several hundred more were expected to arrive Monday when a new fire management team takes over.
The fire has forced the closure of parts of state Route 89.
The Red Cross opened two shelters in the area, at Yavapai College in Prescott and at the Wickenburg High School gym.
Prescott, which is more than 30 miles northeast of Yarnell, is one of the only cities in the United States that has a hot shot fire crew, Fraijo said. The unit was established in 2002, and the city also has 75 suppression team members.