The body of a pilot who was working to fight the Gold Mountain Fire in southwestern Colorado was recovered after a helicopter crash Sunday evening, officials confirmed.

The firefighting helicopter crashed Sunday at around 5 p.m. local time in Gunnison County at the Silver Jack Reservoir, the Sheriff's Office said in a Facebook post. Less than two hours later, a body was recovered but no identity has been released.

It's thought that the pilot was the only person on board, and the helicopter was actively fighting the wildfire, which has grown to more than 56 square miles and was just 11% contained as of Monday morning.

(MORE: Hundreds of homes lost as wildfires rage in Colorado, Utah)

The death happened less than two weeks after three firefighters were killed while battling the Snyder Fire in western Colorado. The three victims were identified as Emily Barker, 38, of Clinton Township, Michigan; Nick Hutcherson, 27, of Glendale, Arizona; and Sydney Watson, 26, of Warrior, Alabama.

According to the Denver Post, more than 1,000 personnel are battling the Gold Mountain Fire. Parts of Gunnison and Ouray counties are under evacuation orders due to the massive wildfire, and evacuation warnings extend into Montrose County.

The cause of the fire is under investigation.