Often when ski patrol is trying to stop avalanches from harming customers of their ski lifts they use explosives of one kind or another

One thing they could do is simply to set off something like a Cherry Bomb and the concussion might send snow down the hill. Or they could shoot blanks with a gun to cause the snow to avalanche before the customers come.

The danger likely would be if they are trying to dislodge something below them without being aware of what is above them that might also go too.

This very likely is what happened here. They might not have been aware that in the altitude above them that that was ready to go in a concussion too from a gun or blast of some kind.

It's lucky they both survived this. However, most people who do this have some backups or radios or ways of surviving an avalanche because the worst problem is breathing under an avalanche. So, if you have an inflation device that keeps a space under the snow so you can still breathe it is the most likely way to survive being covered by an avalanche.

My worst experience in an avalanche was skiing on mountaineering skis (Cross country skis with metal edges for control in icy conditions). I had hiked up to Horse Camp on Mt. Shasta and decided to head East towards Panther Meadows. So, I was at about 10,000 feet or so on Mt. Shasta traversing over towards panther Meadows. But then the snow conditions got too bad and I got too tired to make it there so I just started skiing towards the paved road now covered with snow to ski down the road back to my car towards Bunny Flat which is at about 6900 feet in elevation and as far as the road is plowed during most winters because of snow.

Well. I found that my movements had started an avalanche which was different than I had seen in films. In the one I was in a whole acre of snow started to move down the mountain and I was in the center of it. I was the most worried that I was going to slam into trees at up to 30 mph. However, I was also worried I was going to be sucked under the snow and not be able to breathe.

Also, it was spring skiing so I took my shirt off because it was too hot to wear a shirt working out that hard when I was going uphill. So, I just likely had a hat on and strong sunglasses and pants and boots and skis (the sunglasses prevent snow blindness) (note: when you start to see purple you might be entering a dangerous phase if you are not wearing good sunglasses or ski goggles with eye protection).

So, I was working really hard to try to stay on top of this 1 acre of snow moving down the mountain now gaining speed. 

However, just before I was going to hit trees with my face and body the front part of the acre of snow hit the trees first and slowed the avalanche down and finally stopped the movement completely.

The hardest thing then was that I was cold now from snow up to my chest but the tips of my skis are bent up like most skis and by kicking my skis really hard one at a time I finally was able to break the surface with the tips of both skis (one by one) and using my poles I could then hoist my body up on top of the snow once again. So, I skied down to the paved road covered with snow and knew I would never ski alone above Tree line like this because I had almost died doing this.

If you don't learn from your near death experiences then often you are dead at some point in the future.