Firefighters in Arizona were trying to contain a pair of fast-moving wildfires that destroyed a historic lodge in Grand Canyon National Park, closed a section of the park for the rest of the season and prompted calls for an investigation into federal authorities' wildfire response.

The Grand Canyon was formed with the shifting of tectonic plates, which lifted layers of rock into a high and relatively flat plateau, according to the park service. About 5 million to 6 million years ago, the Colorado River began to carve its way downward, slowly deepening and widening the gorge.