GRAND JUNCTION, Colo. (AP) — A nationally known ice climber who died after falling 60 feet in Colorado over the weekend was attempting to ascend a 365-foot waterfall regarded as one of the toughest ice climbs in the United States.

Jack Roberts, 59, was leading a climb at Bridal Veil Falls on Sunday when he fell, injuring his hip and possibly sustaining internal injuries, authorities said. He survived the long drop but died of cardiac arrest after rescue workers arrived.

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Bridal Veil Falls is at the end of a box canyon near Telluride, a ski resort town where Butch Cassidy robbed his first bank in 1889.

Roberts wrote an authoritative book on ice climbing in Colorado and also worked as a guide and instructor, recently teaching an ice climbing course in Telluride. He climbed for more than 40 years, traveling to Alaska, Argentina and several locations in the Alps.

The Boulder resident was the second person ever to have ascended the falls. In a 2009 YouTube video, he called the climb “special.”

“It offers the climber the opportunity to climb just about anywhere on its surface, and experience climbing in a very unique and special way that becomes more personal than if you’re on the rock,” he said in the video.

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But San Juan Mountain Guides director Clint Cook told the Grand Junction Sentinel that because of how challenging it is, “even when you do everything right, bad things can happen” at Bridal Veil Falls.

According to the Telluride Daily Planet, Roberts’s climbing partner cried for help after the fall. Two hikers who heard the shouts called 911.

The fall wasn’t caused by ice conditions, said Emil Sante, a search and rescue team member who is also San Miguel County’s coroner. An autopsy was ordered for Tuesday morning to find out if the fall was caused by if medical problems. The internal bleeding may have played a role in Roberts’ death, Sante said.

“He said himself that he didn’t know how he fell,” Sante said. “We have a few ideas about what may have contributed to the fall and the speed of his death, but they’re just hunches.”

Roberts is survived by his wife, who was in Cuba with the Boulder-Cuba Sister City Organization when she received notification of the accident.

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