Late-afternoon cloud cover builds with predictable regularity across the desert, accompanied by swirling winds and darkening skies before the downpour begins. While some storms bring only light rain, an August deluge hit a remote stretch of the North Rim of the Grand Canyon with extreme force. Far beneath the rim, scores of trekkers were pitching tents along Bright Angel Creek, looking up at the sheer rock faces they were scheduled to climb on their return journey.
Thick, muddy water quickly surged down the creek bed. A deafening roar echoed off the canyon walls as the torrent slammed against boulders, dragging along fallen limbs, silt, and heavy debris. Fierce summer thunderstorms and sudden flash floods are familiar occurrences across the southwestern region of the United States.
Though campers in the canyon last Saturday were aware of the hazards, this particular storm proved exceptionally destructive, tearing away crucial footbridges and inflicting more structural damage than decades of previous floods combined. The deluge left two people dead and at least one person is still missing. Rescuers evacuated over 80 individuals from the canyon by air, while the National Park Service began evaluating the extent of the destruction.
Extreme weather alerts preceded the deluge, which several survivors characterized in interviews with The as a once-in-a-generation storm. Witnesses detailed rushing to elevated terrain to escape the rising currents, while others sought shelter under rock overhangs to avoid being struck by tumbling stones. "It was for sure some of the worst acute fast-forming weather I have ever seen in my time, whether it’s in the mountains or marine environments or in the desert Southwest," said Drew Harrell, an emergency medicine physician with University of New Mexico Hospital who was on a training mission at the time as medical director for Grand Canyon National Park.
Harrell, who is experienced in remote medical operations and has completed the rim-to-rim trek more than 12 times, had reviewed forecasts alongside his group prior to launching their annual expedition. Their primary concern had been extreme desert heat rising past 100 degrees Fahrenheit, rather than precipitation. However, Harrell noted that the storm materialized almost instantly as his six-person team reached "The Box," a narrow section covering the final 3 miles (4.8 kilometers) before Phantom Ranch, a secluded stop located at the canyon floor.
"It went from relatively clear skies to blowing winds in the time frame of about a minute," he said, estimating the gusts at 40 mph (64 kph). Walkers along the creek were caught off guard as heavy rain, powerful winds, and hail descended in a matter of minutes. "We were concerned that there would be rocks and just flooding coming down from both sides of the canyon on top of us," said Parth Desai, another physician who was with the group.
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