Hot winds blew a U.S. wildfire out of control, killing 19 elite firefighters in the country's deadliest wildfire involving firefighters for at least 30 years. The specially trained "hotshot" firefighters were forced to deploy their fire shelters - tent-like structures meant to shield them from flames and heat - when they were caught near an Arizona town, state forestry spokesman Art Morrison told The Associated Press. Prescott Fire Chief Dan Fraijo said the firefighters were part of the city's fire department. "We're devastated," he said at a news conference Sunday evening. "We just lost 19 of the finest people you'll ever meet." Hot shot crews are elite firefighters who often hike long distances into the wilderness with chain saws and backpacks filled with heavy gear to build lines of protection between people and fires. "By the time they got there, it was moving very quickly," Fraijo told the AP of Sunday's fire. "One of the last failsafe 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 previously listed the deadliest wildland fire involving firefighters as the 1994 Storm King Fire in Colorado. It killed 14 firefighters who were overtaken by a sudden explosion of flames. The fire started Friday and spread to 2,000 acres (809 hectares) on Sunday amid high temperatures and windy conditions. Officials ordered the evacuations of more than 50 homes in several communities.