Firefighters in Arizona were tackling two out-of-control wildfires in extreme heat on Tuesday — including one at the Grand Canyon National Park's North Rim that's forced evacuations, road closures and razed a historic lodge and other structures.

Within days, temperatures soared and humidity dropped, and when winds developed, the fire exploded.

Arizona Governor Katie Hobbs demanded an independent investigation into the federal government's handling of the fire, which was sparked by lightning on July 4.