Fire rages after nineteen elite firefighters confirmed dead in Yarnell, Arizona FIREFIGHTERS struggled to contain a runaway wildfire in the US state of Arizona after 19 of their comrades were killed in one of the worst such incidents in US history and two towns were evacuated. The firefighters died while racing to contain the Yarnell Hill wildfire about 135 kilometres north of Phoenix, in what Arizona Governor Jan Brewer called "as dark a day as I can remember." US President Barack Obama paid tribute to those who lost their lives, in a statement issued while traveling in South Africa which lamented "this terrible tragedy." The Yarnell Hill fire, believed to have been ignited by lightning and fanned by high winds, broke out Friday and has swept across 2000 acres (809 hectares), spreading rapidly through the dry, forested area. Prescott Fire Chief Dan Fraijo had earlier said he was "devastated" by the loss of lives. Sunday's deaths also mark the largest loss of firefighter lives on US soil since the 9/11 attacks on the World Trade Centre, when 340 firefighters were killed, according to NFPA statistics. Federal help was set to arrive on Monday, local news site the Arizona Republic reported, but officials expected at least 250 homes - about half the town of Yarnell - would be destroyed by the inferno. Speaking to a local NBC affiliate Sunday, she added: "When we get these drought areas, sometimes it dries out, it just burns so quickly and so fast and tonight is another example of that. A state forestry official told CNN the firefighters, from an elite local "hotshot" crew, had been digging a fire line to contain the blaze. "Evidently, their safety zone wasn't big enough, and the fire just overtook them," Art Morrison said. A Facebook page has been created in memory of the fallen firefighters, showing a picture of the Granite Mountain Hotshots crew from Prescott, Arizona, with 19 people in the photo. This devastating loss is a reminder of the grave risks our firefighters take every day on our behalf in Arizona and in communities across this nation. Their sacrifice will never be forgotten," Arizona Senator John McCain said in a statement. The Yarnell Hill wildfire is the worst of several blazes raging across the arid state and comes two weeks after a blaze in Colorado killed two people and burned down 360 homes, that western state's most destructive blaze ever. Record and near-record temperatures left much of the US southwest sweltering over the weekend, with Death Valley in California equaling the hottest ever June temperature in the United States, at 128 degrees Fahrenheit (53 Celsius). The wildfire season in the southwest flared up earlier than usual this year, with California, Arizona and New Mexico the hardest hit.