Strangest fact
In 1959 nine hikers cut their tent open from the inside and fled into minus 25 degree cold without proper clothes. Some were found with crushed chests and skulls.
Why it is odd: Skilled winter hikers left their only shelter in the dark, which means something seemed worse than freezing.
In late January 1959, ten young skiers and hikers, most of them students or graduates of the Ural Polytechnic Institute, set out on a hard winter trek in the northern Ural Mountains led by Igor Dyatlov. One man turned back sick on January 28. The other nine set up camp on the slope of a mountain called Kholat Saykhl, which means "Dead Mountain" in the local Mansi language, and never came back.
Searchers found the tent 26 days later, half buried in snow. It had been cut open from the inside. The bodies were found over the following weeks and months, more than a kilometer downslope near the forest. The hikers had fled in temperatures below minus 25 degrees Celsius, some barely dressed and without boots. Most died of hypothermia, which means the body getting too cold to work. But four had severe chest or skull injuries, two were missing their eyes and one the tongue, and traces of radioactivity were found on some clothing.
The 1959 Soviet investigation closed the case saying that a compelling natural force
caused the deaths, without saying what that force was. The mix of strange details fed many theories over the years, including secret weapons tests, attacks, infrasound (very low sounds that some say can cause panic), and even yetis.
Russian authorities reopened the case in 2015. In 2019 the Investigative Committee concluded that a snow avalanche was the most likely cause, and the Prosecutor General's office reached the same conclusion in July 2020. Many people doubted it, because the slope looked too gentle for an avalanche and searchers had not seen avalanche debris.
In 2021, Johan Gaume of the Swiss university EPFL and Alexander Puzrin of ETH Zurich published a study in Communications Earth and Environment. Using computer models, they showed how a small slab of snow could break loose hours after the hikers cut into the slope to make a flat spot for the tent, once strong winds had piled extra snow above it. Such a slab, they found, could cause severe but not instantly fatal chest and skull injuries. Later expeditions measured parts of the slope at more than 30 degrees and filmed small slab avalanches there. Puzrin has said they never set out to provide absolute closure on the case.