Blackcomb, Horstman peak

I was boot-packing up horstman peak east ridge with a group of 5 students. As a training exercise to follow up after a self arrest and general step kicking and ice axe use session. Day 8 of a 20 day course. The ridge was a mixture of shallow snow cover with rocks poking through to thigh deep powder. Interspersed with hard wind slab that I had to kick steps in. 3/4 of the way up the short hike I triggered a hard wind slab that went to ground on basal facets. The entire limited variable depth seasons snow pack released to the ground. The bed surface tore talus blocks along with it. Crown 20-100 Cm. 30 M wide. 220 M long. Size 2. There were no involvements. We witnessed the whole thing. Although an accidental. Hiking not skiing. I immediately contacted blackcomb dispatch via phone to report the incident. Patrol responded within a couple of minutes searching the debris and responding to the event.