Abnormally dry, hot conditions near the Grand Canyon's North Rim allowed the Dragon Bravo Fire to grow rapidly.

Nearly 400 firefighters are working around the clock on the Dragon Bravo Fire burning on the North Rim of Grand Canyon National Park, Tuesday.

Partial blue skies in the morning allowed many park visitors to ignore fires on the North Rim. By afternoon, ashfall made for a different story.

Arizona's governor has demanded an investigation into why a wildfire that destroyed a historic lodge and dozens of other structures on the North Rim of the Grand Canyon was allowed to burn for a week before federal firefighters tried to put it out.

Authorities maintained the evacuation zones for the White Sage Fire north of the Grand Canyon as the fire grew expectantly.