Two helicopter pilots who crashed while fighting a wildfire in Utah have been confirmed dead, officials said, after their Sikorsky S-64 Skycrane went down while battling the massive blaze.

The helicopter was among several aircraft deployed to fight the Widemouth 2 fire in Fishlake National Forest when it crashed near Richfield, about 160 miles south of Salt Lake City.

Pilots confirmed dead after crews reach crash site

Officials initially said emergency crews were unable to reach the crash site because of dangerous fire conditions. Crews later entered the area and confirmed the deaths, according to the Sevier County sheriff and coroner.

The pilots were employed by Helicopter Transport Services, which was contracted by the US Forest Service. Their identities have not been released.

The crash also sparked a new fire that eventually merged with the existing blaze, authorities said.

Massive Utah wildfire continues to spread

The Widemouth 2 fire has burned more than 114,600 acres, or nearly 179 square miles, and was 24% contained. The blaze has expanded rapidly amid hot, dry and windy conditions.

More than 600 firefighters have been battling the fire, which has prompted evacuations and destroyed at least six structures.

The National Transportation Safety Board is investigating the helicopter crash. Investigators are expected to examine the wreckage once conditions allow. Officials said determining the cause of the crash could take a year or more.

Deadly wildfire season hits US West

The Utah crash occurred as wildfires continued to spread across several western US states.

In Oregon, 47-year-old bulldozer operator Jason Ensign was killed while working for a timber company as the Wrights Spring fire rapidly expanded and cut off his escape route.

The fire had burned more than 30 square miles and remained uncontained amid extremely hot and dry conditions.

Other major fires were also burning in Washington, while a wildfire in British Columbia forced more than 20,000 people to evacuate.