Residents of Arizona are reeling from the deaths of nineteen firefighters yesterday -- members of an elite firefighting team who perished while battling a fast-moving wildfire.

The victims were members of the Granite Mountain Crew, a squad of highly trained firefighters who specialized in wilderness fires and had battled blazes in several western states in recent months. News sources are reporting that in an effort to save themselves, the men deployed emergency fire shelters intended to shield them from the heat and offer breathable air.

The fire – believed to be started by a lightning strike – has destroyed approximately 200 buildings in the small town of Yarnell, about 85 miles northwest of Phoenix.

President Barack Obama issued a statement in which he called the men “heroes.” Arizona Gov. Jan Brewer said it was “as dark a day as I can remember.”

“This tragic event is one of the deadliest wildfire incidents in the U.S. in at least 30 years,” said the American Industrial Hygiene Association (AIHA), in a statement. “Our thoughts are with the families of the victims and their communities.

“Employers are responsible for the safety of their workers and must do everything they can to protect workers from the hazards associated with the response and recovery operations for wildfires.The Occupational Health and Safety Administration website has several resources to help workers and employers prepare for wildfires, as well as information on hazards that may be present in areas affected by wildfires. These include safety hazards like unstable structures and heavy equipment and health hazards like heat stress, hazardous materials and carbon monoxide."