Dyatlov Pass incident

The Dyatlov Pass incident (Russian: Гибель тургруппы Дятлова, romanized: Gibel turgruppy Dyatlova, lit. 'Death of the Dyatlov Hiking Group') was an event in which nine Soviet ski hikers died in the northern part of the Ural Mountains ridge in the Russian SFSR of the Soviet Union on 1 or 2 February 1959 under undetermined circumstances. The experienced trekking group from the Ural Polytechnical Institute, led by Igor Dyatlov, went on a hike of the highest difficulty level at that time, and had established a camp on the eastern slopes of Kholat Syakhl mountain. Overnight, the group cut their way out of their tent by knives and fled the campsite, inadequately dressed for the heavy snowfall, strong winds and extreme cold temperatures as low as −40 °C (−40 °F). After the group's bodies were discovered, an investigation by Soviet authorities determined that six of them had died from hypothermia while the other three had been killed by physical trauma. One victim had major skull damage, two had severe chest trauma, and another had a small crack in his skull. Four of the bodies were found in May 1959 lying in running water in a creek, and three of them had damaged soft tissue of the head and face — two of the bodies had missing eyes, one had a missing tongue, and one had missing eyebrows. The investigation concluded that a "compelling natural force" had caused the deaths. Numerous theories have been put forward to account for the unexplained deaths, including animal attacks, an avalanche or loud slab avalanche to their tent, appearance of a UFO or ball lightning, katabatic winds, infrasound-induced panic, conflict with local ethnic groups or fugitive criminals, a botched spy meeting with representatives of the Western bloc, military rocket- and nuclear-testing involvement, or some combination of these factors. Russia reopened an investigation into the incident in 2019, concluding in 2020 that an avalanche had most likely forced survivors to suddenly leave their camp in low-visibility conditions with inadequate clothing before ultimately dying of hypothermia. Andrey Kuryakov, deputy head of the regional prosecutor's office, stated that "It was a heroic struggle. There was no panic, but they had no chance to save themselves under the circumstances." A study led by scientists from EPFL and ETH Zürich, published in 2021, suggested that a type of avalanche known as a slab avalanche could explain some of the injuries. A mountain pass in the area later was named "Dyatlov Pass" in memory of the group, despite the incident occurring about 1,700 metres (5,600 ft) away on the eastern slope of Kholat Syakhl. A prominent rock outcrop in the area now serves as a memorial to the group. It is about 500 metres (1,600 ft) to the east-southeast of the actual site of the final camp.