A party of 3 was snowmobiling in the Thunderwater Lake riding area on a slope above Whirlpool Lake. Two riders were involved in the avalanche that was reportedly triggered near a rocky feature on the slope. One rider managed to ride off to the side, the other was caught and buried approximately 2 meters deep on a bench feature mid-path. The subject was located and extricated by their party and CPR initiated. Search and Rescue responded and evacuated the subject via helicopter to BC Ambulance Service in Invermere, but the victim did not survive.
The avalanche was reported to be a storm slab over a crust. It occurred on an alpine feature above a lake and was 40-100 cm deep, 100 meters wide, and 300 m long.