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

Dozens of buildings inside the North Rim of the Grand Canyon have been destroyed, including a historic lodge, as a chlorine gas leak has forced firefighter evacuations from the Dragon Bravo Fire.

The Grand Canyon Lodge was one of dozens of structures destroyed in a fast-moving wildfire in Arizona over the weekend, the National Park Service confirmed.