An already dangerous forest fire in Arizona turned into a death trap when a sudden windstorm sent it out of control, leading to the deaths of 19 firefighters, authorities said Monday.

It was the nation's biggest loss of firefighters in a wildfire in 80 years.

Though the names of the victims had not yet been released by early Monday afternoon, one of the squad leaders was Phillip “Mando” Maldonado, and a relatively new member was Shane Arollado, according to a profile of the group that appeared last year in the Tucson Sentinel.

“These guys kinda become my family,” Maldonado said last year. “I saw them more than I saw my girlfriend last year.”

Prescott Fire Chief Dan Fraijo said he was devastated. 

"Emotionally? We’re devastated," Fraijo said at a news conference late Sunday. "We just lost 19 of some of the finest people you’re ever going to meet. Right now we’re in crisis. ... Truly, we’re going through a terrible crisis right now.”

The flames swept over the victims Sunday evening as they took cover in their foil-lined emergency shelters.

The lone survivor the elite firefighting crew escaped because he was moving the crew's truck when the flames roared over the men, authorities said Monday.

"This is as dark a day as I can remember," Arizona 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."

The windblown, lightning-sparked fire — which had exploded fourfold to about 13 square miles by Monday morning — also destroyed dozens of homes and sent hundreds fleeing from Yarnell, a town of 700 people about 85 miles northwest of Phoenix.

Efforts are underway to bring the United States Honor Flag to Prescott to honor the fallen firefighters.

A public memorial service is planned for the Embry Riddle Aeronautical Center in Prescott, according to Channel 3 News.

Residents huddled in shelters and restaurants, watching their homes burn on TV as flames lit up the night sky in the forest above the town.

The fire killed 18 members of a hotshot crew based in nearby Prescott, plus a firefighter who was not part of the unit, Arizona Forestry Division spokesman Mike Reichling said.

Southwest incident team leader Clay Templin says the crew and commanders were following safety protocols, but it appears the fire's erratic nature simply overwhelmed them.

The team had spent recent weeks fighting fires in New Mexico and Prescott before being called to Yarnell, entering the smoky wilderness over the weekend with backpacks, chainsaws and other heavy gear to remove brush and trees as a heat wave across the Southwest sent temperatures into the triple digits.

"We grieve for the family. We grieve for the department. We grieve for the city," Fraijo said.

A makeshift memorial of flower bouquets and American flags formed at the Prescott fire station where the crew was based. Prescott resident Keith Gustafson showed up and placed 19 water bottles in the shape of a heart.

"When I heard about this, it just hit me hard," he said. "It hit me like a ton of bricks."

Hotshot crews go through specialized training and are sent in to battle the nation's fiercest wildfires. Sometimes they hike for miles into the wilderness with heavy gear to build lines of protection between people and fires. They remove anything that might burn in the direction of homes and cities.

As a last-ditch effort at survival, members are trained to dig into the ground and cover themselves with a tent-like shelter made of fire-resistant material, Fraijo said.

"It's an extreme measure that's taken under the absolute worst conditions," the fire chief said.

Reichling said all 19 victims had deployed their shelters.

Arizona is in the midst of a historic drought that has left large parts of the state highly flammable.

Television aerial video footage showed law enforcement vehicles patrolling Yarnell, driving streets with burned buildings on both sides.

The last time so many were killed in a wildfire was in the 1933 Griffith Park fire in Los Angeles, which killed 29, according to the National Fire Protection Association. The biggest loss of firefighters in U.S. history was 343, killed in the 9/11 terrorist attack in New York.

In 1994, the Storm King Fire near Glenwood Springs, Colo., killed 14 firefighters who were overtaken by a sudden explosion of flames.

President Barack Obama called the 19 people heroes and said in a statement that the federal government was assisting state and local officials.

"We are heartbroken about what happened," he said.

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 Red Cross opened two shelters in the area — one at Yavapai College in Prescott and the other in a high school gym.

The Associated Press contributed to this report.

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