Very well written story on NY Times about the Avalanche at Tunnel Creek (near Stevens Pass in Washington State). Very well designed site and impressive multimedia integration that you should 'experience' it yourself.
http://www.nytimes.com/projects/2012/snow-fall/
I think the article and the site won several awards!
(Interview with author/developers on how the story/site was made - http://source.mozillaopennews.org/en-US/articles/how-we-made-snow-fall/)