SANTA FE, N.M. (AP) — A flash flood that transformed a series of idyllic, azure waterfalls into a monstrous brown froth was ferocious but not unusual for the summer rainy season on the Havasupai reservation, one of the most remote reaches of the continental U.

S. that attracts visitors worldwide. But this time the rush of water that sent hundreds of hikers scrambling for high ground — some within nooks and caves in the canyon walls — turned deadly.

A woman was swept away toward the Colorado River within the Grand Canyon, touching off a dayslong search and rescue effort involving the National Park Service in a unique environment beyond the reach of cellphones, within desert canyons accessible only by foot, mule or helicopters. Three days later and 19 miles (30 kilometers) downstream, a recreational river-rafting group would resolve the search. Afterward, survivors and rescuers clung to stories of shared grief, gratitude and respect for waters that turned unexpectedly violent.

First rain, then chaos The day of the flash flood began before dawn for hikers descending into a verdant canyon on an 8-mile (13-kilometer) trek along switchback trails to a village in the heart of the Havasupai reservation. From there, tourists walk toward their bucket-list destinations — a series of majestic waterfalls and a creek-side campground. The canyon’s normally blue-green waters draw tourists from around the world.

Physical therapist Hanna St. Denis, 33, traveled from Los Angeles to see.