A water treatment facility at the North Rim had been compromised by the fire, causing chlorine gas to fall to the bottom of the Canyon.

The visitor center and a wastewater treatment plant were among the 50 to 80 structures lost, the park superintendent said. The area was evacuated Thursday.

Heavy winds that swept through Black Canyon of the Gunnison National Park on Sunday night started “rapid fire spread” after a relatively slow day of growth, according to fire officials.

Gov. Katie Hobbs (D-AZ) questioned the federal government’s handling of the fires burning the Grand Canyon, which have spread rapidly and destroyed dozens of buildings. Two wildfires, the White Sage Fire and the Dragon Bravo Fire,