The ground just starts cracking right in front of the snowboarder. I mean, what do you even do when the ground fractures and the snow murmurs and life glitches like that? What do you do when you have two seconds to realize you're screwed and to come up with a plan to unscrew yourself? You can't do anything, really.
This GoPro video shows an avalanche forming right before a snowboarder's eyes. It's insane.