A technical rescue effort was required Saturday to reach a man who had died while climbing Telluride’s Via Ferrata.

The 76-year-old Grand Junction man suffered a life-threatening medical event while climbing, according to a press release from the San Miguel Sheriff’s Office.

He had just completed the “Main Event,” the most technical portion of the Via Ferrata about 4 p.m. when he sat down on a narrow ledge and became unresponsive.

His step-daughter started CPR, called 911 and yelled for help.

Telluride Fire Protection District EMS and Fire personnel, San Miguel County Sheriff’s deputies and Telluride deputy marshals were dispatched to the scene. Because of the remote location, responders had to hike through treacherous terrain to reach the patient.

A guided tour group on the Via Ferrata heard the woman’s cry for help and came to assist with CPR. After a total of nearly 45 minutes of resuscitative efforts, the man was pronounced dead about 4:45 p.m., according to the press release.

Sheriff deputies and a dozen search and rescue volunteers executed a five-hour, highly technical recovery mission in cliff terrain.

“I am proud of the collaborative efforts of our first responders. Certainly this is an unfortunate outcome, and our thoughts are with the victim’s family,” said Telluride Fire Protection District Chief John Bennett.

The cause and manner of death were being investigated by the San Miguel County Coroner, per protocol. Trauma was not a contributing factor, officials said.

The Via Ferrata sits at the East End of Telluride’s box canyon on the south side of Ajax Peak accessing a natural ledge system via man-made iron rungs and steel cables. Climbers use harnesses and a tether system connected to a cable while traversing a cliff side using iron rungs attached into the cliff.

The increasingly popular “climbing trail” traverses horizontally with extreme exposure 400 feet above the mountainside.

“Given our mountainous environment, we encounter incidents that require time and technical skills on treacherous terrain,” said San Miguel Sheriff Bill Masters.