Over 50 people have died from Snow in Japan

http://news.yahoo.com/video/world-15749633/japan-braces-for-more-snow-28156676.html

Most of the 50 people died while on their roofs pushing the snow off before their roofs collapsed. When they fell into the snow and weren't rescued they froze to death. By falling into the 10 or 12 feet of snow on the ground it would be sort of like falling into an avalanche. You wouldn't be able to move and unless someone heard you there would be a good chance of either freezing to death or not being able to breathe in that much snow. I suppose people could wear snow shoes but that might be counter productive because they would also make people slip off the roofs and into the snow more as well. So, as you can see that much snow is very dangerous and unpredictable. Likely the best bet would be to work always with two people one on the roof and one spotting on the ground so they could call for help in a real emergency.