'After the avalanche took the life of Blake Morstad, it also left Sam Kavanagh hanging on by a thread in very dangerous circumstances. Still deep in the backcountry, Sam was hemorrhaging blood from his mangled leg. With weather conditions remaining unfavorable for rescue, the odds were mounting against his survival. In Part Two, Sam retells the story as it unfolded around him. Also, Doug Chabot of the Gallatin National Forest Avalanche Center, first on the scene after the avalanche hit, walks us through the chain of events leading up to the accident. What natural forces triggered the avalanche? What exactly is buried surface hoar ? Most importantly, what is the human element - the stoke of the day, as Sam calls it, and how can we be aware of it?'