It's a horrifying site, but at 0:35 you can see snow from an avalanche cascade over the top of a man walking down a slope while he and his friends are snowmobiling at Stampede Pass.
According to KING 5, the man caught in the avalanche, identified as John, had stopped at the bottom of the hill to watch a friend higher up on the slope.
His friends quickly run to his aid and are able to dig him out before he spends no more than 45 seconds without air.
The Forest Service's National Avalanche Center does have three tips for snowmobilers when they're out in avalanche-prone terrain: Only expose one person at a time to the avalanche terrain and watch your partners from a safe location out of the avalanche run out zone; look for signs of unstable snow, especially recent avalanches; make sure everyone in your group carries rescue gear.
A map of current avalanche zones in Washington can be found here.