A flash flood in a remote area of the Grand Canyon has left at least 20 people missing or unaccounted for, including around a historic lodge near the site’s bottom, officials reported on Sunday.

The National Park Service is requesting information about individuals hiking or backpacking along Bright Angel Creek, and campers planning to stay at Phantom Ranch or Bright Angel Campground. Efforts are also aimed at locating travelers stranded on the North Kaibab Trail.

By Sunday morning, 62 individuals were evacuated from Phantom Ranch and the lower part of the North Kaibab Trail. Further evacuations from Phantom Ranch and Cottonwood Campground were anticipated.

Park administrators reported that footbridges along Bright Angel Creek were destroyed, removing hiker access across the creek. Certain Colorado River crossings are also closed while damage assessments are underway.

The flash flood resulted in significant impacts to infrastructure throughout Bright Angel Canyon.

Remnants of stone bridge pylons remain after the flash flood took out the footbridge on August 29.

Phantom Ranch, accessible only by hiking, rafting, or mule transport, has been a sought-after destination since its opening in 1922. Traffic on the Colorado River is suspended due to floating debris risks.