First, a loud whumpf roars through the valley, slamming my entire body with the malicious ferocity of a kick drum beat at an underground club. Next, terrifying silence as the slope gives way underneath. The snowpack crumbles before it turns to a mushy gunk the consistency of hand-cranked cement as it pours down the face of the mountain. I didn’t even see it coming. It is 10:45am on Monday, April 2nd. I’m three-quarters of the way up Sherwin Ridge, and my climbing partner, Ryan, is about to be hit by 1,100 tons of sludge.