From Public ob, "Third rider in party triggered a slab avalanche approximately 3’ deep and 200’ wide running approx 400.’ Third rider was swept the entire way. Resurfaced as debris fanned out, unharmed. 1st and 2nd rider posted up in small treed island further away were affected by snow impact including partial burial. 4th in party watched from above maintaining safe distance. No injuries, safe ride out."
May have been triggered well-below crown. Estimated crown depth of least 1m deep on the looker's left side, 40-60cm deep on the right.