... A video posted to YouTube on Sunday showed Sallison's harrowing run: he begins a descent in a mid-sized couloir, makes two sharp turns, cracks appear in the top layer of snow, and then 50-foot slabs sluff off the mountain, consuming Sallison as he tumbles down the mountain, his body popping in and out of visibility as he struggles to stay above the snow.
... Weather conditions had changed overnight with wind packing parts of the face with a layer of snow that could be susceptible to a slide, it's a process called "wind-loading" which Avalanche.org calls a "common denominator in most avalanche accidents" since the wind can lead to rapid snow accumulation.
Moreover, wind-loaded snow is denser than free-falling snow, forming a more dangerous layer that also fractures easily.
On top of that, Sallison admitted several more mistakes that he now regrets: not checking radio batteries, not making a game plan beforehand, and not planning a line out to safety.
