have already killed four people.

Gotta register them slopes over 30 degrees from the horizontal.  Yeah, that'll do the trick, by gum.

I don't know about you, but I didn't get to be 73 years old by deliberately entering dangerous situations.

I swear some of these folks go up there and measure the slope and if it's only 29° 59' 59" they figure it's safe to go blasting around on their snowmobiles and enjoying pristine nature while cross-country skiing.  Yee-haw!

This is from 2010 but is almost identical to a recent situation where two brothers got caught, one survived.



This guy rode one down:



Very sad:

http://www.thedenverchannel.com/news/30279345/detail.html

(I think the cause of death there was suffocation, not asphyxiation.)

Folks who've been buried and survived say they cannot tell which way is up, so can't struggle to a definable  surface.  Probably not unlike getting tumbled in a wave while surfing.



Terry, just ramblin', 230RN
ETA:

What caliber for avalanches? As you may be aware, various agencies use various kinds of artillery (cannons, mortars, even rockets) to start avalanches so they won't be dangerous later. 

This one is funny. (LATER:  I take that back.  I found out later that over 100 people were killed, including the camera crew and the soldiers involved.  Sorry.) As they say, "In Russia, avalanche not kill you.  You kill avalanche. Or not."

I don't know about you, but I didn't get to be 73 years old by deliberately entering dangerous situations.

Everything's been done these days. You need to go even further to do things that are 'unique' now. Regular things just aren't exciting enough.

Back when I used to ski, I remember hearing about how dangerous avalanches were and always heard them blasting the mountains outside the skiing areas. I never got close to an avalance, but never doubt the power of nature.