One person has died and 15 others are missing or unaccounted for after flash flooding tore through the Grand Canyon's Bright Angel Canyon and Phantom Ranch area on Saturday afternoon, destroying footbridges and sending boulders downstream. The National Park Service said the body of a 46-year-old man was recovered on Sunday evening near Crystal Rapids along the Colorado River, while 62 people have been airlifted to safety, including hikers who described scenes of panic as rangers guided them to higher ground before evacuation late that night.

The flooding stems from the North American monsoon season, in which warm, moist air pulled north from the Gulf of California and the tropical Pacific triggers sudden, hard-to-forecast storms over dry, mountainous terrain, causing dangerous flash floods. Flood watches remain in place across large parts of Arizona, New Mexico, Utah and Colorado, with further thunderstorms forecast and the threat expected to persist for weeks, as the monsoon season typically runs until the end of September. The park service has closed affected trails, suspended overnight lodging at the South Rim due to "extensive damage" to water infrastructure, and is appealing for information on hikers who were in the inner canyon on Saturday.