It's the aliens, Unexplained deaths

Dyatlov Pass Incident


In the late 1950s, a group of Russians who were very experienced ski-hikers were discovered to have died on the slopes of the Mountain of Death, some of them frozen to death and others dead from massive physical trauma. They left their camp in the middle of the night, some without clothing or shoes, in sub-zero weather. What terror caused them to flee to their deaths?

Some of our research:
A practical review
Crackeds’ take on things
Wiki post