One of the most famously arid national landmarks succumbed to deadly flash flooding over the weekend, leaving at least one person dead and more than a dozen unaccounted for as more rain is set to pummel Grand Canyon National Park in Arizona on Monday.

A 46-year-old man’s body was found near Crystal Rapids along the Colorado River, park officials said Sunday night.

And about 15 people could be missing after “nearly all footbridges spanning Bright Angel Creek were destroyed, eliminating hiker access across the creek,” the National Park Service said.