CONGRESS, Ariz. — Nineteen firefighters were killed on Sunday battling a fast-moving wildfire menacing a small town in central Arizona.

The firefighters died fighting the Yarnell Hill Fire near the town of Yarnell, about 80 miles northwest of Phoenix. Steve Skurja, a spokesman for the Yavapai County Sheriff’s Office, said there were “several fires still active” in the Yarnell area. In a search of the scene, Mr. Skurja said, crews found the bodies of the firefighters.

They were members of the Granite Mountain Hotshots, a specialist team of wildfire fighters based in Prescott, Ariz., said Mike Reichling, a spokesman for the Tempe Fire Department. He declined to identify the men until their families had been notified.

“This is as dark a day as I can remember,” Arizona’s 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,” she said. “When a tragedy like this strikes, all we can do is offer our eternal gratitude to the fallen, and prayers for the families and friends left behind. God bless them all.”

President Obama issued a statement Monday as he was ending a visit to South Africa and flying to Tanzania. “Yesterday, 19 firefighters were killed in the line of duty while fighting a wildfire outside Yarnell, Ariz. They were 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.

“Michelle and I join all Americans in sending our thoughts and prayers to the families of these brave firefighters and all whose lives have been upended by this terrible tragedy.”

Image Credit... The New York Times

The firefighters had to deploy their emergency shelters when “something drastic happened,” Fire Chief Dan Fraijo of Prescott told The Associated Press.

The crew killed in the blaze had worked other wildfires in recent weeks in New Mexico and Arizona. The unit was established in 2002.

In a Facebook post, the United States Wildland Fire Aviation Service asked “for prayers for the families and friends of these brave men and women.”

Until Sunday, Arizona had suffered 21 firefighter fatalities in wildfires since 1955, according to the National Interagency Fire Center.

“It started on Friday with a lightning strike, and it’s grown,” Mr. Reichling said, citing weather conditions on Sunday. The fire is spread across “well over 2,000 acres,” he said, and had “brought down half of the town of Yarnell. It has decimated that town.”

The town had been evacuated previously, he said. A reverse 911 call was sent, and sheriff’s deputies alerted residents.

Flames were traveling north, away from the small community of Yarnell, 4,800 feet up a mountain between Wickenburg and Prescott, in central Arizona. Some residents there left to go to neighboring Peeples Valley, where an evacuation order was in place, to help people pack up and leave their homes. Others stayed behind, watching the parched bush burn in the distance or, like Nina Bill Overmyer, 66, taking a nap.

Suddenly, the wind shifted and the flames changed direction, rushing through the forest straight toward Yarnell. Ms. Overmyer’s husband, Chuck, woke her up and they picked up what they could. He took his motorcycle. She took their Dodge truck, pulling the flatbed trailer bearing their lime-green Model A street rod, one of their most prized possessions. By the time they came back to get their dogs, the blaze was roaring just above them, rolling down the mountain and swallowing everything around: the town’s library, community center, diner.