The five students and their guide in the advanced avalanche class had a detailed plan for the second day of their three-day course. They set waypoints where decisions would be reviewed. They planned their route to avoid avalanche hazards. They dug a snow pit to identify potential instability in the snowpack. They studied avalanche forecasts and weather reports.
They were doing everything right until the descent from a saddle below South Telluride Peak, just above 13,100 feet. The guide from Silverton Avalanche School skied first. Peter Marshall, a 40-year-old father, husband and son from Longmont, followed. Four more skiers above Senator Beck Basin, northwest of Red Mountain Pass near Silverton sidestepped down the slope to watch the two skiers.
The pair of simultaneous avalanches on Jan. 5 caught all six skiers. The guide was partially buried. Four others were swept down the slope. Marshall was buried more than 8-feet deep. It took the team 50 minutes of aggressive shoveling to reach him. Resuscitation efforts failed.
Marshall was Colorado’s first avalanche fatality of the 2018-19 season and the second-ever fatality involving a student in an American Institute for Avalanche Research and Education class.
A report issued Wednesday by the Colorado Avalanche Information Center details the group’s day, illustrating how the tiniest lapse in focus while traveling in avalanche terrain can yield tragic consequences.
“This accident is especially troublesome as it involved a group of well-trained and well-equipped people in an avalanche safety class,” reads the report.
The report reveals not only all the things the group did correctly, but, as part of the institute’s mission to better educate skiers so they can avoid avalanches, it also highlights the group’s mistakes.
A tenet of safer travel in avalanche terrain is to expose only one skier at a time to hazards.
“The group failed to plan and execute their descent in a way that minimized their exposure to a potential avalanche and that allowed the members to communicate. They chose to descend the first slope to the bench spaced apart, with multiple skiers on the slope,” reads the report.
The group was focused on avoiding avalanche terrain. Early in their ascent, they identified a dangerous, snow-loaded aspect and avoided it by climbing up a slope with more shallow snow. They chose a similarly south-facing slope for their descent.
“They descended this area and the results were tragic. What was different?” asks the report, which was compiled by CAIC executive director Ethan Greene and three other avalanche forecasters.
Jan. 5 was the first day that CAIC lowered its avalanche danger ranking from “considerable” to “moderate.” CAIC’s Jan. 4 and Jan. 5 forecasts for the terrain around Red Mountain Pass noted the potential for big slides and remote triggers, pointing to the slopes along the U.S. 550 corridor as particularly susceptible to avalanches breaking on buried weak layers.
“You can trigger avalanches from the bottom of the slope, from adjacent slopes, or from a distance,” reads the Jan. 5 forecast.
After the accident, members of the group said they were trying to avoid slopes steeper than 30 degrees to reduce their risk. But they did not measure the angle of the slope the group chose to descend. The CAIC researchers measured the angle and found the slope ranged from 32 to 34 degrees. Digital GPS maps the group used showed the slope as less steep and thus less avalanche prone.
If the group had measured the slope angle, the report said it was possible they would have recognized the increased danger.
“On some days and with some avalanche problems, the difference between 29 degrees and 32 degrees might not be significant. However, it can be significant when dealing with a persistent slab avalanche problem, especially when a remote trigger is possible,” Greene’s report reads.
Marshall was wearing an avalanche airbag. The CAIC researchers found the airbag was functioning. It just wasn’t deployed. Another skier in the group also was wearing an avalanche airbag but the bag did not inflate when he pulled the trigger as he was swept down the slope. The report said the skier had assembled the trigger mechanism incorrectly.
In 2005, a student in the second day of an AIARE Level 2 class offered by Aspen Expeditions was killed in an avalanche in the Five Fingers Bowl outside the Aspen Highlands ski area boundary. That group also had carefully planned its descent, digging snow pits and testing the snow stability. John Jensen, a telemark skier from New Mexico, veered toward a gully when he fell down the slope and the snow around him collapsed, triggering an avalanche that carried him more than 3,000 feet down the mountain.
Jensen’s death was the first avalanche fatality in the history of Aspen Expeditions, just as Marshall’s death was a first for the venerable Silverton Avalanche School, which formed in 1962.
Introspection provides insight
The avalanche safety industry is dutifully introspective. Accidents are painstakingly detailed and analyzed to provide potential insights that might help others avoid avalanches. In the last four seasons, a decline in avalanche fatalities in Colorado and across the West can be partially credited to a renewed focus on avalanche safety anchored in the hard lessons of previous avalanches. The avalanche that killed Marshall — described in a Silverton Avalanche School website post as “a diligent and safe backcountry skier” — will resonate across the avalanche education world.
“This tragic accident will cause our industry to look inwards and to re-evaluate our practices. What the consequences of introspection might be, I don’t know,” said veteran Colorado avalanche educator Dale Atkins. “I do know the Silverton Avalanche School offers high-quality programs lead by top professionals.
“As you know, working and recreating in avalanche terrain is about managing uncertainty, and this accident tragically highlights the perils of uncertainty. I don’t know the details of this accident, but when dealing with uncertainty, even the best processes of knowledge and skills are sometimes imperfect,” he said. “When the best and brightest suffer mishaps, it reveals the deadly seriousness of avalanches, and that the rest of us should double our efforts to improve our knowledge and skills.”
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