In February 1959, a group of ten students from the Ural Polytechnical Institute went on a hiking expedition in the Ural mountains.  Nine of the ten died in what has come to be known as the Dyatlov Pass Incident. The area was later named after the group’s leader, Igor Dyatlov.  One of the students turned back due to illness, the other nine (seven men, two women) continued on their journey.

During the night of February 2, something happened that resulted in the violent deaths of three party members (fractured skulls, internal injuries) and caused the deaths of the others by hypothermia after they abandoned their tent at night, without winter gear on, and with gusting winds and low visibility.  Soviet investigators arrived at the site a month afterward.  Despite their efforts, they had no coherent explanation, and eventually the case was closed by summer.  Ludicrous conspiracy theories were postulated over the years, none based on any evidence.

In 2019, Russian investigators reopened the case.  With input from other scientists and the investigator’s own work, in January 2021 an avalanche has been named the most likely culprit.  The avalanche theory makes a lot of sense and explains most of the events and the group’s actions.  Feral animals could explain other details the avalanche can’t (e.g. missing eyes and tongues from some of the bodies).

NatGeo: Has science solved one of history’s greatest adventure mysteries?

The bizarre deaths of hikers at Russia’s Dyatlov Pass have inspired countless conspiracy theories, but the answer may lie in an elegant computer model based on surprising sources.

A 62-year-old adventure mystery that has prompted conspiracy theories around Soviet military experiments, Yetis, and even extraterrestrial contact may have its best, most sensible explanation yet—one found in a series of avalanche simulations based in part on car crash experiments and animation used in the movie Frozen.

In an article published today in the journal Communications Earth and Environment, researchers present data pointing to the likelihood that a bizarrely small, delayed avalanche may have been responsible for the gruesome injuries and deaths of nine experienced hikers who never returned from a planned 200-mile adventure in Russia’s Ural Mountains in the winter of 1959.

My own (wrong) theory was ergot poisoning from bad food or something similar. The timing of the event (hours after their last meal) and certain actions (cutting open the tent from the inside, going out without proper clothing, violence) could have been explained by hallucinogens.