BANFF, Alberta (AP) — Three renowned mountain climbers are presumed dead after an avalanche in Alberta’s Banff National Park, Canadian officials said Thursday.

Outdoor apparel company The North Face said that American Jess Roskelley and Austrians David Lama and Hansjorg Auer disappeared while attempting to climb the east face of Howse Peak. They were reported overdue on Wednesday.

Roskelley climbed Mount Everest in 2003 at age 20. At the time he was the youngest American to climb the world’s highest peak.

The North Face says it is doing what it can to support the climbers’ families and friends.

Officials say recovery efforts are on hold because of a continued risk of avalanches.