Only one survivor from hotshot unit trained to venture into remote areas, which was overtaken by rapidly moving blaze
Nineteen firefighers have died in Arizona after being caught in one of the deadliest wildfires in the US for decades, which destroyed scores of homes and forced the evacuation of two small towns north-west of Phoenix
The specially trained "hotshot" firefighters were forced to deploy their fire shelters – tent-like structures meant to shield them from flames and heat – when they were caught near an Arizona town, state forestry spokesman Art Morrison told the Associated Press.
"The entire hotshot crew had been killed by the fire," Prescott fire chief Dan Fraijo said.
"We're devastated," he said at a news conference on Sunday evening. "We just lost 19 of the finest people you'll ever meet."
Morrison told CNN: "In normal circumstances, when you're digging fire lines, you make sure you have a good escape route, and you have a safety zone set up. Evidently, their safety zone wasn't big enough, and the fire just overtook them. By the time the other firefighters got in, they didn't survive."
"This is as dark a day as I can remember," state governor 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."
Hotshot crews are elite firefighters who often hike long distances into the wilderness with chain saws and backpacks filled with heavy gear to build lines of protection between people and fires.
"By the time they got there, it was moving very quickly," Fraijo told Associated Press of Sunday's fire.
"One of the last failsafe 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 ... 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% chance that they survive," he said. "It's an extreme measure that's taken under the absolute worst conditions."
He said one member of the 20-man crew happened to be in a separate location and survived. There was no immediate information on his condition.
The Daily Courier Prescott newspaper said the dead were members of the Prescott Fire Department's Granite Mountain Hotshots team.
The blaze erupted on Friday near the small town of Yarnell about 80 miles north-west of Phoenix. It had spread to 800 hectares (2,000 acres) by Sunday amid high temperatures, low humidity and windy conditions. Officials ordered the evacuations of more than 50 homes in several communities.
The tragedy ranks as the greatest loss of life among firefighters from a single wildland blaze in the United States since 29 men died battling the Griffith Park fire of 1933 in Los Angeles, according to National Fire Protection Association records.
Local television news footage showed an unbroken line of flames stretching along a ridgeline, sending smoke billowing into the evening sky.
Authorities ordered the evacuation of Yarnell and the adjoining town of Peeples Valley, alerting residents through reverse 911 emergency calls to homes and sending sheriff's deputies door to door. The two towns are home to about 1,000 people.
Steve Skurja, spokesman for Yavapai County Sheriff's Office, said at least 200 structures had been destroyed by the fire, most of them in Yarnell, which is populated largely by retirees.