Date of Event: 9/18/2012

Canyon involved: Subway

Region: Zion National Park, Utah

Country: USA

Submitted by: Dave Nally

Source: “Deaths & Rescues in Zion National Park” by Dave Nally

Injury: Fatality

Cause: Anchor error, Rappel error, Inexperience, Hypothermia, Hanging upside down

Description of Event: On Tuesday, September 18, 2012. Seventy-four-year-old Yoshio Hosobuchi and his wife were descending the Subway, making the last drop into the popular and photographic slot portion of the canyon. The retired neurosurgeon’s rappel device jammed, and he became stuck upside-down in a waterfall after he attempted to cut himself out of his climbing harness waistband with a knife. For some unknown reason, he chose to cut his harness waistband instead of cutting the rope. When he cut the harness, his body slipped upside-down, and his leg straps became entangled around his ankles. His elderly wife, who had reached the canyon bottom first, could reach up and touch his fingertips as he hung. She was not able to climb back up to assist him, so she headed down canyon for help. Zion National Park Chief of Interpretation, Aly Baltrus, said that neither Hosobuchi nor his wife was an experienced canyoneer, but they were not complete novices either.


“They actually had taken a course―just an introductory course on canyoneering, which we recommend to everybody. They had also gone through Keyhole Canyon first, which is a much easier descent,” she said. Rescuers are not sure why Hosobuchi decided to use the log anchor to descend the waterfall. Perhaps he did not see the standard anchors nearby that allow for rappelling down a ramp 30 feet for the final drop. Once stuck on the rope, due to the accidental jamming of his safety device known as an auto-block, he might not have had the experience to recover. An auto-block is an extra precaution useful to add friction and safety, in case the rappeler accidentally lets go of the rope with their brake-hand side. An auto-block is often recommended and useful on long, overhanging drops, but is usually not used for short drops; nor is it recommended while rappelling through flowing water.


Another canyoneer, who had passed Hosobuchi in the canyon prior to the accident, noted that the couple was moving at a slow pace, and he thought that they would likely not reach the exit by nightfall. That person alerted park rangers at about 9 p.m. Tuesday. However, the park staff opted not to launch a full-scale search at night―not realizing that the tragedy had already taken place.


Hosobuchi’s wife gradually made her way down canyon, but was unfamiliar with the Subway exit route, and did not manage to make contact with rescuers until late Wednesday morning. By the time rescuers reached Hosobuchi in the Subway, he had perished. A helicopter retrieved his body from the canyon on Thursday. It was believed that hypothermia, exposure, and complications from spending a prolonged amount of time inverted on the rope were contributing factors.

Analysis:

  • Anchor choice

  • Autoblock is expert technique

  • Autoblock no good in moving water

  • All canyoneers should have the skill and gear to ascend a rope. The equipment to ascend needs to be readily available on the harness.