The fire still burned late Sunday, with flames lighting up the night sky in the forest above Yarnell, a town of about 700 residents about 85 miles northwest of Phoenix. Most people had evacuated from the town, and no injuries or other deaths were reported.
The fire started after a lightning strike on Friday and spread to at least 2,000 acres on Sunday amid triple-digit temperatures, low humidity and windy conditions.
Prescott Fire Chief Dan Fraijo said that the 19 dead firefighters were a part of the city's fire department.
"We grieve for the family. We grieve for the department. We grieve for the city," he said at a news conference Sunday evening. "We're devastated. We just lost 19 of the finest people you'll ever meet."
Hot shot crews are 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 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."
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.
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, or the Rattlesnake blaze four years later that claimed 15 firefighters in Southern California.
President Barack Obama called the 19 firefighters heroes and said in a statement that 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 on Monday.
Chuck Overmyer and his wife, Ninabill, said they lost their, 1,800-square-foot home in the blaze.
They were helping friends flee when the blaze 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. It was zero percent contained late Sunday.
The Red Cross has 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.
Billeaud reported from Phoenix. Associated Press writer Brian Skoloff in Yarnell, Ariz., and Associated Press reporter Martin Di Caro in Washington, D.C., also contributed to this story.
Obama sends condolences for firefighters who died
President Barack Obama says the deaths of 19 firefighters who died battling an Arizona wildfire are a heartbreaking reminder that emergency personnel put their lives on the line every day while rushing toward danger.
Obama, who spoke from Africa on Monday, added that America's thoughts and prayers go out to their families.
He said, quote, "We are heartbroken about what happened."
Obama says his administration is prepared to help Arizona investigate how the deaths happened. He predicted the incident will force government leaders to answer broader questions about how they handle increasingly destructive and deadly wildfires.
The firefighters, members of an elite crew fighting a forest fire northwest of Phoenix, were overtaken Sunday by a fast-moving blazed fueled by hot winds. Some 200 homes also were destroyed.
Man watched home burn in fire that killed 19
An Arizona man who lost his home in a wildfire that killed 19 people says he saw embers on the roof of his garage in his rear view mirror as he fled.
Chuck Overmyer says he and his wife, Ninabill, left with their three dogs and a 1930 model hot rod on a trailer. They gathered at a nearby bar and grill along with other people and watched on TV as their 1,800-square-foot home went up in flames.