DENVER (CBS4)– The Colorado Avalanche Information Center has completed their investigation into a deadly slide in southwest Colorado. Peter Marshall was participating in a Silverton Avalanche School class when two slides buried him.

(credit: CAIC)

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The avalanche happened Jan. 5 on Senator Beck Basin on Red Mountain Pass. The CAIC investigation reveals that there were two separate avalanches that hit the group.

Marshall, 40, from Longmont was buried and killed in the slide. Marshall was one of six in a group taking part in a Silverton Avalanche School Recreation Level Two training course when the slide hit.

(credit: CBS)

According to the report from the CAIC, the group involved were made up of highly trained and well prepared skiers.

The report states, “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. The waiting skiers had to side step over the break in slope to maintain visual contact with the descending skiers.”

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(credit: CAIC)

According to his obituary, Marshall was a father, brother and husband who lived in Longmont and was an avid backcountry traveler. He was found buried face down in nearly 10 feet of snow from the two avalanches.

Ethan Greene, Director of CAIC, said this is a tragedy that highlights just how dangerous traveling through avalanche zones can be, even for seasoned experts.

(credit: CBS)

According to the report, “The skiers triggered the first slide- it sent the group’s avalanche class instructor and Marshall, who was following him second in line, down the debris field to the bottom of the slide. It also caught the other four skiers but they ended up closer to the top of the debris field and were able to self-rescue. Next, a crack moved through the snow and triggered a second slide, that avalanche overlapped the first debris field, a key factor to why it took rescuers nearly 50 minutes to reach Marshall.“

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The Silverton Avalanche School says this is the first fatal incident they have had since the nonprofit was founded in 1962. It was also the first deadly avalanche incident in Colorado this season.