Sorry for necromancing, but I was reading about this last night again and there was a new investigation in Russia this year that concluded the cause of the incident was some sort of avalanche, or avalanche-like effect that forced the campers to flee their campsite. Lots of questions remain still, but this seems like a good summary:
Dyatlov Pass incident - Wikipedia
For me, the biggest question is whether or not the Soviets were testing military technology that day (there were reports of orange spheres in the sky around the same time) and if those files are still being supressed if so. Testing missiles/parachute mines would have certainly caused some sort of panic or concern.