Montreal’s Gabriel Filippi was one of the Canadian climbers on Mount Everest when Saturday’s earthquake in Nepal, which caused more than 3,800 deaths in the country, triggered an avalanche that killed at least 18 people and injured many more on the mountainside. In this video, recorded from Everest’s southern base camp the day after the earthquake, Filippi describes the scene that followed the disaster. Many of the reported deaths at Everest were from base camp. An unknown number of climbers were farther up the mountain when the earthquake struck, and have been stranded there. Helicopters have been evacuating survivors from the mountainside since Sunday. Several climbers are still unaccounted for. Saturday, April 25, 2015, is now believed to have been the deadliest day on Everest.