mountainside of snow suddenly gave way. as you can see, numerous skiers were on the slope at the time. some were able to outrun the avalanche. but six people got caught. avalanches in the alps were not uncommon but this was unusual. it was on a well -used ski slop where the risk was not considered high. for more about it, here's scott mclane from london. >> these skiers from the swiss alps are probably lucky to be alive after getting caught in an avalanche that nobody saw coming. video taken in a nearby gondola captured the avalanche as it started to slide. if you look closely, those little black dots are people. some are safe off to the side. two of them managed to outrun the slide on their skis. and according to local authorities six people were swallowed up. amazingly, four were able to dig themselves out, while a search