Wildfire ... a house is engulfed by the wildfire in Yarnell
NINETEEN firemen have been killed in Arizona in the worst tragedy to hit a US crew battling a wildfire in 80 years.
The elite force were killed as they took cover under a fire shelter as the deadly blaze ripped through Yarnell Hill, Arizona on Sunday. President Obama broke away from his state visit to South Africa to call the men "heroes" who had "selflessly put themselves in harms way to protect the lives and property of fellow citizens." 
Flames ... a resident of Yarnell watches as the blaze destroys buildings
The hotshot crew had been fighting the fire sparked by lightning bolts as the south west of the US experienced an extreme heat wave. They had sought safety under protective covering as the fire ripped through the town, 85 miles north west of Phoenix.
Tragedy ... the hotshot crew
It was the largest death toll for a force from a single wildland blaze in the US since 29 men died battling the Griffith Park fire in Los Angeles in 1933. It’s the biggest loss of life from a single incident for a US fire department since 9/11.
Brave ... fire crews prepare to tackle the blaze
Prescott Fire Department Chief Dan Fraijo said: "Our entire crew was lost. We're devastated. We just lost 19 of the finest people you'll ever meet."
The fire started on Friday and picked up momentum as the area experienced high temperatures, low humidity and windy conditions.
Fraijo explained: “One of the last fail safe 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 fire-resistant material with the desire, the hope at least, that the fire will burn over the top of them and they can survive it.
“Under certain conditions there's usually only sometimes a 50 per cent chance that they survive. It's an extreme measure that's taken under the absolute worst conditions."
Devastating ... the wildfire was sparked by lightning bolts
The firefighters were members of a hotshot crew, tasked with digging a firebreak and creating an escape route. Forestry spokesman Art Morrison said: "A hotshot crew are the elite firefighters.
"They're usually a 20-person crew, and they're the ones who go in and dig the fire line, cut the brush to make a fuel break. And so they would be as close to the fire as they felt they safely could."
Tribute ... speaking from South Africa, President Obama called the firefighters 'heroes'
More than 200 firefighters are still battling the fast-moving wildfire, which has scorched 2,000 acres. An estimated 200 homes were destroyed in Yarnell, almost half of the town.
