The names of 19 firefighters killed fighting a massive wildfire in Yarnell, Ariz., on Sunday night have been released. The men were killed attempting to contain the Yarnell Hill Fire, which began sometime on Friday and has consumed as many as 500 buildings across 8,300 acres northwest of Phoenix. Their deaths made the Yarnell Hill Fire the single deadliest event for American firefighters since Sept. 11, 2001.

On Monday, the Associated Press released the firefighters' names as Kevin Woyjeck, 21; Chris MacKenzie, 30; Billy Warneke, 25; Scott Norris, 28; Andrew Ashcroft, 29; Clayton Whitted, 28; Anthony Rose; 23, Eric Marsh, 43; Robert Caldwell, 23; Dustin Deford, 24; Scott Misner, 26; Garret Zuppieger, 27; Travis Carter, 31; Grant McKee, 21; Travis Turbyfill, 27; Jesse Steed, 36; Wade Parker, 22; Joe Thurston, 32, and John Percin, 24. 

The firefighters were all part of the Prescott Fire Department’s elite Granite Mountain Hotshots team. Only one member of the 20-person team survived the Yarnell Hill Fire. The vast majority of the firefighters killed in the Yarnell Hill fire were under 30 and eager to do their jobs.

According to the Associated Press, Woyjeck joined the Granite Mountain Hotshots in an attempt to emulate his father, a 30-year veteran of the Los Angeles County Fire Department. 

"He wanted to become a firefighter like his dad and hopefully work hand-in-hand," LACFD inspector Keith Mora told the Associated Press Monday at a Seal Beach, Calif., fire station, near where the Woyjeck family lives.

The 19 fallen firefighters were mostly “hotshots” who dig fire lines designed to stop advancing blazes. The firefighters were apparently unable to set up a properly sized safety zone and could not escape the rapidly approaching fire in time. 

"It was a hand crew, a hot shot crew," Arizona forestry official Art 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.”

Initially, the firefighters were reported missing until the U.S. Wildland Fire Aviation service confirmed their deaths.

In an official statement, President Barack Obama described the firefighters as “heroes -- highly-skilled professionals who, like so many across our country do every day, selflessly put themselves in harm's way to protect the lives and property of fellow citizens they would never meet.”

“In recent days, hundreds of firefighters have battled extremely dangerous blazes across Arizona and the Southwest,” Obama continued, according to NBC News. “The federal government is already assisting, and we will remain in close contact with state and local officials to provide the support they need.”

The Yarnell Hill Fire likely began as a result of a lightning strike on Friday. Due to record-high temperatures in the Southwest, strong winds, and a lack of rain, the fire quickly spread from the isolated Yarnell Hill toward the small town of Yarnell. More than 8,300 acres and as many as 500 buildings have been destroyed by the wildfire as residents of Yarnell and nearby Peeples Valley have been evacuated from the area. Approximately 1,000 people live in the area.

The U.S. Forest Service was expected to take command of firefighting efforts Monday evening, the Arizona Republic reported. Once the fire is under the federal agency’s control, it shifts from a “Type 2 fire” commanded by the Arizona State Forestry Division to a “Type 1 fire,” considered the most serious

A Facebook group honoring the deceased firefighters went live on Sunday night and earned well over 100,00 supporters within hours.