This New Yorker article covers the most recent, always-definitive research on the mysterious deaths of the Dyatlov party.
In 1959 a group of adventure-seeking, experienced outdoors young Russians, led by Igor Dyatlov, were not just found dead but oddly mutilated, near a campsite that seemed like it was just fine — minus the frantic slashes in their tent made as they apparently scrambled away.
This research suggests their tent became partially covered by a sliding shelf of snow, injuring some of the party and invoking fear of a massive avalanche in the others. Viewed from this scenario, the rest of their response seems logical, and sadly, insufficient.
The most appealing aspect of Kuryakov's scenario is that the Dyatlov party's actions no longer seem irrational. The snow slab, according to Greene, would probably have made loud cracks and rumbles as it fell across the tent, making an avalanche seem imminent. Kuryakov noted that although the skiers made an error in the placement of their tent, everything they did subsequently was textbook: they conducted an emergency evacuation to ground that would be safe from an avalanche, they took shelter in the woods, they started a fire, they dug a snow cave. Had they been less experienced, they might have remained near the tent, dug it out, and survived. But avalanches are by far the biggest risk in the mountains in winter, and the more experience you have, the more you fear them. The skiers' expertise doomed them.
It probably wasn't aliens.
