Nineteen firefighters dead in the Yarnell Hill wildfire that spread from eight acres to 2,000 acres overnight in Central Arizona 19 elite firefighters confirmed dead near Arizona town of Yarnell 200 homes burned in the fast-moving blaze caused by lightning strike President Obama declared the firefighters 'heroes' Approximately 600 people are under mandatory evacuation from the area More firefighters are on their way to help combat the wildfire By Ashley Collman and Becky Evans At least nineteen firefighters were killed when an Arizona blaze became out of control on Sunday, killing the elite crew in the deadliest wildfire involving firefighters in the U.S. for at least 30 years. The 'hotshot' firefighters were forced to deploy their emergency fire shelters - tent-like structures meant to shield firefighters from flames and heat - when they were caught near the central Arizona town of Yarnell, state forestry spokesman Art Morrison said. The average age of the firefighters was just 22. The fire also destroyed an estimated 200 homes, Morrison said. Dry grass near the communities of Yarnell and Glen Isla fed the fast-moving blaze, which was whipped up by wind and raced through the homes, he said. Engulfed: 19 firefighters died as the wildfire spread near the Arizona town of Yarnell Tragedy: The crew deployed emergency fire shelters to try to protect them from the blaze Destroyed: At least 200 homes in Yarnell have burned down as the blaze gained momentum Heroes: 18 of the 19 firefighters killed were from the Prescott Granite Mountain Hotshot crew (pictured) Today, President Obama said the firefighters were heroes and highly skilled professionals who 'put themselves in harm's way to protect the lives and property of fellow citizens they would never meet.' Mr Obama, who is travelling in Africa, says the federal government would be in close contact with state and local officials in Arizona to provide support. The tragedy is the deadliest single incident for firefighters since the September 11, 2001 terrorist attacks, officials said. They were overtaken by a fast-moving blaze stoked by hot winds yesterday. The fire was still burning late yesterday, with flames lighting up the night sky in the forest above Yarnell, a town of about 700 residents about 85 miles northwest of Phoenix. Most people had evacuated from the town, and no injuries or other deaths were reported. The fire started after a lightning strike on Friday and spread to at least 2,000 acres on Sunday amid triple-digit temperatures, low humidity and windy conditions. Prescott Fire Chief Dan Fraijo said that the 19 dead firefighters were a part of the city's fire department. Long-term: Firefighters expect to be in the area battling the blaze for at least a week Evacuation: Hundreds of residents were forced to flee their homes Death toll: The Yarnell wildfire is the deadliest wildfire involving firefighters in the U.S. for at least 30 years Catastrophe: About half the homes in the small town of Yarnell have been lost in the wildfire Heartbroken: Prescott Fire Chief Dan Fraijo said the firefighters were 'the people you'll ever meet' The 19 firefighters died as they battled the flames in Yarnell, Arizona We grieve for the family. We grieve for the department. We grieve for the city,' he said at a news conference Sunday evening. 'We're devastated. We just lost 19 of the finest people you'll ever meet.' Hot shot crews are elite firefighters who often hike for miles into the wilderness with chain saws and backpacks filled with heavy gear to build lines of protection between people and fires. They remove brush, trees and anything that might burn in the direction of homes and cities. The crew killed in the blaze had worked on other wildfires in recent weeks in New Mexico and Arizona, Fraijo said. 'By the time they got there, it was moving very quickly,' he said. He added that the firefighters had to deploy the emergency shelters when 'something drastic' occurred. '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 - 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 per cent chance that they survive,' he said. 'It's an extreme measure that's taken under the absolute worst conditions.' The National Fire Protection Association had previously listed the deadliest wildland fire involving firefighters as the 1994 Storm King Fire near Glenwood Springs, Colorado, which killed 14 firefighters who were overtaken by a sudden explosion of flames. Trapped: The 19 firefighters could not escape the fast-moving flames Plumes of smoke: Thick grey smoke rises from raging wildfires in the hills near Yarnell Devastation: Almost half the town's homes have been damaged or destroyed in the blaze Dangerous: Firefighters spray water on a restaurant to help protect it from flames in the Glenn Ilah area Battle: Pockets of flames burn on the horizon as fire crews assess the situation U.S. wildfire disasters date back more than two centuries and include tragedies like the 1949 Mann Gulch fire near Helena, Montana, that killed 13, or the Rattlesnake blaze four years later that claimed 15 firefighters in Southern California. 'This is as dark a day as I can remember,' Gov. 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. Brewer said she would travel to the area on Monday. Two hundred firefighters were working on the fire Sunday, but several hundred more were expected to arrive Monday when a new fire management team takes over. The fire has forced the closure of parts of state Route 89. It was zero per cent contained late Sunday. Fast-moving: The fire started with a lightning strike on Friday and spread to 2,000 acres on Sunday Deadly: Soaring temperatures and low humidity helped the flames spread over the weekend Aid: The Red Cross has set up a shelter at the Yavapai College in Prescott, Arizona The Red Cross has opened two shelters in the area - at Yavapai College in Prescott and at the Wickenburg High School gym. Prescott, which is more than 30 miles northeast of Yarnell, is one of the only cities in the United States that has a hot shot fire crew, Fraijo said. The unit was established in 2002, and the city also has 75 suppression team members. Chuck Overmyer and his wife, Ninabill, said they lost their, 1,800-square-foot home in the blaze. They were helping friends flee when the blaze switched directions and moved toward his property. They loaded up what belongings they could, including three dogs and a 1930 model hot rod on a trailer. As he looked out his rear view mirror he could see embers on the roof of his garage. 'We knew it was gone,' he said. Escape: Homeowners packed up any belongings they could as they fled the wildfire Backup: 200 firefighters and four planes are battling the blaze with 130 more firefighters on their way Departed: The firefighters killed in the incident were members of the Prescott Fire Department Highly trained: Members of the Granite Mountain Hotshots (pictured last year) had been fighting wildfire in New Mexico and elsewhere in Arizona in the past few weeks He later gathered at the Arrowhead Bar and Grill in nearby Congress along with locals and watched on TV as he saw the fire destroy his house. 'That was when we knew it was really gone,' he said. He later fielded a phone call from a friend in which he said, 'Lost it all, man. Yep, it's all gone.' Morrison said the fire grew in intensity when winds began gusting at up to 24mph in the late afternoon. 'You get some winds, and it can take off on you,' he said.