In the winter of 1959, nine grad students (two women and seven men) set off on a holiday ski-hike expedition in the Ural Mountains. They never made it home.
Igor Dyatlov—after whom the case is named—organized a trip to explore the Otorten mountain slopes in the northern part of the Ural range. The plan set a group of experienced ski hikers out to the Soviet wilderness on January 27, 1959. The group originally consisted of 10 members but Yuri Yudin left the expedition a day later due to illness. The team of nine decided to continue with the expedition to reach the mountain, trekking through what would later come to be known as 'The Dyatlov Pass.' However, due to worsening conditions—snowstorms and decreasing visibility— they lost their direction and decided to set camp on the eastern slope of Kholat Syakhl. That same night, on February 2, 1959, all nine members died under mysterious circumstances.
The Dyatlov party had informed some of their peers that they hoped to return around February 12, but that it was expected to take longer. Because expeditions often experienced delays, there was no immediate reaction when the 12th passed with no messages. It wasn't until a few days after—and with the insistence of the hikers' relatives—that a rescue group was sent to the location.
On February 26, a search party found the group's camp site and were left baffled by their discovery. Investigators found that the group's tent had been sliced open from the inside; it was also apparent that the tents were quickly abandoned, as their belongings had been left inside. The party also found footprints from eight or nine people, heading in the direction of the tree line. The group's shoes were also left behind: These footprints confirmed that some walked with socks while others were barefoot. Investigators followed the tracks leading towards the forest and stumbled upon a horrifying sight.
At the forest's edge, searchers discovered the first two bodies; those of Krivonischenko and Doroshenko, shoeless and wearing only their undergarments. At the time of their death it would have been -30°C (-22°F). Within three weeks, investigators had found five bodies some hundreds of meters away from the original site. It appears that Dyatlov and company had tried to make their way back to the encampment, only to die near a burned out fire about a mile from the tent. Their bodies were dusted with a few inches of snow.
It would take an additional two months before the remaining four travelers were found. Their bodies were partially clothed with articles belonging to the earlier discovered bodies and with high levels of radiation. These last four bodies appeared to have suffered traumatic deaths, having been discovered down a ravine (about 17 feet deep) in a cave they had dug, while trying to take shelter from the cold. Nicolas Thibeaux-Brignollel had a fractured skull. Alexander Zolotaryov had crushed ribs. Lumila Dubinina also had broken ribs, and her tongue was missing.
It is possible the injuries are the result of falling into the ravine, but that doesn't explain Duninina's missing tongue. Besides freezing to death—five died of hypothermia—no cause has ever been confirmed. In the end, lead investigator Lev Ivanov provided a vague conclusion, "The cause of death was an unknown compelling force which the hikers were unable to overcome." Such a vague conclusion led to many unanswered questions.
What in the world could’ve caused Dyatlov party to go out of their minds and rush to their deaths in the freezing cold?
Theories range from avalanches and UFOs, to undisclosed nuclear testing in the area (this did happen in the Cold War-era Soviet Union, after all). Here are a few of the most popular theories.
The dangers of avalanches are quite common in the region. A portion of the upper layer of snow could have shifted and rolled over the tourists. This would explain the disaster, the cut out tent, and some of the physical trauma. An avalanche would damage the tent and wreak havoc amongst the group, who might then decide to cut the tent open in order to escape the snow and avoid getting trapped. It would also reveal the reason the group left their belongings—including their shoes—behind. However, this theory has its gaps. The naked footprints left behind indicate that the group moved with ease. The Dyatlov party included many experienced and skilled ski hikers who would know how to react to a situation like this. Also the tent did not demonstrate any signs of damage from an avalanche. A middle portion of the tent did collapse, but it is likely that was due to the weight of the snow that had collected there.
Considering the secrecy, radioactivity, and the appearance of some bodies: They were described as "deeply tanned". There is speculation that the camp site fell within the path of a Soviet parachute mine. The theory claims that the hikers panicked when they heard loud explosions. This led them to flee their tent quickly—out of fear, they left their belongings behind. When they attempted to return to their site they realized they were lost. There are records of parachute mines being tested around the location and time of the group's expedition. That would explain some of the unnatural manipulation of some of the bodies and the orange skin and grey hair of others. Furthermore, Soviet suppression of the files appeared to be a cover-up in order to conceal domestic incidents. However, radioactive dispersal would have affected all of the hikers not just some, and by the late 1980s, all Dyatlov files had been released.
20-50% of hypothermia deaths are associated with paradoxical undressing. This occurs during moderate and severe hypothermia, when the person becomes disoriented, confused, and combative. In the victim's delirium, they may suffer from hot flashes causing them to undress. This symptom sadly only leads to a quicker death. It is a plausible reason for the group's death, as hypothermia would be the leading cause. It was confirmed that six of the nine hikers died of hypothermia. However, the last four found had acquired clothing from those who had already died. If they had enough layers on, what caused their death?
Logicians have explained away the fractured limbs and internal injuries by pointing out the bodies found were at the bottom of a rather steep cliff. And as for the lost tongue, scientists and investigators have said it is likely the result of decomposition and putrefaction due to the melting snow–although some reports still maintain it was ripped from the mouth.
Whatever really happened, our takeaway is clear: Avoid Siberian snow camping expeditions–especially those on the Dyatlov Pass–at all costs.