A desperate search was underway Sunday for at least 15 missing hikers who vanished when a flash flood swept through the Grand Canyon.

The National Park Service (NPS) confirmed 46-year-old man was dead and many others missing as they continued scouring the popular retreats of Bright Angel Canyon and Phantom Ranch after the torrent struck at 2:30 p.m. Saturday.

Apocalyptic footage showed a stream of water wiping what appeared to be a building downstream as the wall of mud was surged through the ravine.

Dramatic rescue video also captured helicopter pilots carrying people to safety as the rainstorm battered the chopper and the extent of the devastation could be seen below.

In an update Sunday afternoon, the Grand Canyon National Park Service issued a request for information about 20 missing people, before a spokesman later revised the figure to 15.

It said: “The National Park Service is asking the public to provide information for more than 20 individuals who may be missing or unaccounted for following a significant flash-flood event in Bright Angel Canyon and the Phantom Ranch area on August 29. (Read more from “At Least 15 Hikers Missing as Flash Flood Sweeps through Grand Canyon” HERE)

Photo credit: Flickr