An aerial view of a section of the town of Yarnell, Arizona that is destroyed by a wildfire which ripped through the town is seen on July 1, 2013. [Photo/Agencies]

Running Out of Time

The firefighters deployed their personal shelters, capsule-like devices designed to deflect heat and trap breathable air, in a last-ditch effort to survive, officials said.

Andersen said some of the men on the ground made it into their shelters and some did not, according to an account relayed by a ranger helicopter crew flying over the area.

"There was nothing they (helicopter crew) could do to get to them," he said.

Prescott Fire Department Chief Dan Fraijo said hotshot crews typically establish a secure "safety zone" to which they can retreat if flames start to close in on them.

Authorities ordered the evacuation of Yarnell and the adjoining town of Peeples Valley. The two towns are southwest of Prescott and home to roughly 1,000 people.

Officials said on Sunday at least 200 structures, mostly homes, had been destroyed, most of them in Yarnell, a community consisting largely of retirees, but the figure could rise.

The so-called Yarnell Hills blaze was one of dozens of wildfires in several western US states in recent weeks in what experts say could be one of the worst fire seasons on record.

Arizona Forestry Commission spokesman Mike Reichling said one member of the 20-man crew had been driving in a separate location and survived unhurt.

Evacuee Rick McKenzie, 53, a bow hunter and ranch caretaker, said the fire exploded on Sunday with flames 30 to 40 feet (9 to 13 meters) high. He said he had warned the Hotshots about the dense oak woods where they would be working.

"I said, 'If this fire sweeps down the mountain to the lower hills where all this thick brush is, it's going to blow up, guys, you need to watch it,'" McKenzie said.