Sorry to hear about your friend. That has been such a big fear of mine over the years. I have been in a small avy and its pretty scary to think what something bigger would be like. I'm more into snowmobiling in the deep stuff, but I do know that these air bags have saved a lot of lives. I would recommend one of these over an avy lung. Why worry about trying to breath with concrete on top of you, if you can have a 90%+ chance of getting on top of that crap. Of course knowing the conditions and staying away is always better.