Two theories for an unsolved Soviet mystery

This is the last photo taken by a group of experienced Russian hikers, the night they disappeared in February 1959. Here, in the remote Ural Mountains in Western Siberia. They were on an advanced winter hiking trip, covering hundreds of miles across a frozen desert. The photo shows them digging a platform in deep snow to pitch their tent along the slope of Kholat Syakhl, which translates from the language of the region's indigenous people, the Mansi, as Dead Mountain. Hours later, the hikers abandoned the tent and all their equipment in the darkness. Weeks later, a search party found the store half destroyed and covered in snow.

They had opened it from the inside. Frozen bodies were found 1,500 meters away, most of them barefoot and dressed only in sleeping clothes. Which means something drove the group out of the tent so quickly that there wasn't even time to unbutton the entrance or put on the heavy winter gear needed to survive the conditions outside. It would take another 2 months to locate the rest of the group. All of them dead, their autopsies revealed serious injuries that were difficult to explain. Dozens of

theories

have since been developed, from extraterrestrial encounters to government cover-ups. But basically all

theories

try to answer the same question: What made them leave the store in the first place?

The deeper you delve into the Dyatlov Pass incident, named after the group's leader, 23-year-old Igor Dyatlov, the less things tend to add up. So, for the sake of this video and to explain what potentially happened that night, let's focus on the most basic facts. This is a rough diagram showing where the bodies of the 9 hikers were found in relation to the abandoned tent, made from maps hand-drawn during the initial investigation and from descriptions in the case files. The bodies were found in three groups. These six died of hypothermia, the rest of traumatic internal injuries. These two images will help piece together a picture of what happened to the group after they left the store.

The search party found footprints leading away from the tent that disappeared into the snow after about 500 m. Continuing in their direction, the first two bodies were found. Under a cedar tree, 1,500 m downhill from the store. They were wearing almost nothing and had lit a small fire. They froze to death. Then three more were found in a straight line from the tree, as if they were trying to return to the tent. Which, with temperatures of -30 degrees and without proper clothing, was practically impossible. They also froze to death. The last four were not found until about 2 months later.

Buried under four meters of snow in a ravine. And this is where the research starts to get more confusing. Because, unlike the rest of the group, three of them had experienced severe internal trauma. Dubinina and Zolotaryov had several broken ribs and Thibeaux-Brignolle had a major skull fracture. Internal injuries that his autopsy reports determined were fatal. The investigation's forensic expert compared his injuries to “trauma resulting from the blast wave of a bomb.” But there was more. Zolotaryov and Dubinina were missing their eyes, and Dubinina was missing her tongue. She and Kolevatov were wearing clothing contaminated with excessive amounts of radioactive substances.

Despite many unanswered questions, top Soviet investigator Lev Ivanov closed the case on May 28, 1959. He concluded that no crime had been committed, citing that the hikers had no external injuries and that all his valuables were intact. And that the cause of death was “an overwhelming force, which the hikers could not overcome.” Since then, dozens of theories have tried to explain what happened that night in 1959: the murder at the hands of the KGB. A Yeti attack. Soviet military experiments went wrong. And, of course, UFOs. Most of these theories lack substantial evidence. And some of the most disturbing elements of the case aren't so mysterious after all.

The missing soft tissues, Zolotaryov and Dubinina's eyes and Dubinina's tongue, for example. Their bodies were found in a stream, and Dubinina in particular was found face down. The coroner concluded at the time that these were “post-mortem changes” due to natural decomposition after months of exposure to running water. But two theories in particular, each involving “overwhelming force,” offer plausible solutions to the two most important questions in the case. What led the hikers to leave the tent the way they did and what could have caused the tremendous internal injuries some of them suffered. One of these theories has been considered and debunked for years.

Avalanche. Because this area is not considered avalanche-prone, and the internal injuries do not match those typically found in avalanche victims, who mostly die from asphyxiation after being swept through the snow, this theory is often has been ignored. But a scientific paper published in January 2021 shows that hikers could have been affected by a very specific type of avalanche. GAUME: My name is Johan Gaume, I am a professor at the Swiss Federal Institute of Technology and I study snow avalanches. Johan Gaume and his colleague, geotechnical engineer Alexander Puzrin, developed a model that simulates a rare type of avalanche that could have hit the store.

A delayed slab avalanche. FILE: The entire slab moves almost instantly. As it runs downhill, it breaks into large blocks. At its actual speed, it is obvious why the wind plate is called the “big killer.” A slab avalanche occurs when a large concentration of snow forms on top of a weak, less concentrated layer. GAUME: And when the weak layer fails, this failure will propagate along the slope and eventually trigger a slab avalanche. In the Dyatlov case, the trigger for an avalanche of plates would have been cutting the slope to set up the tent. But whatever took them down the mountain happened hours later.

GAUME: We think the strong winds brought some additional snow on top of the tent. And this caused a progressive accumulation and, finally, the failure of the weak layer, and the avalanche that impacted the tent and the hikers. And we showed that this type of impact could explain the injuries of some of the hikers. Trapped under the slab, and potentially fearing a second avalanche, they left the tent and headed to the tree line for cover. This theory, built from simulations and data-driven models, shows that a delayed slab avalanche was possible under these conditions and could explain the traumatic injuries within the group.

And he doesn't try to explain anything beyond what got them kicked out of the store, like why the group was so poorly dressed. GAUME: We say that this is possible, that an avalanche of this type would have hurt them in the same way as them. Everything that happened after the avalanche is outside the scope of our article. HOLMGREN: It is not difficult to die in Kholat Syakhl, on Dead Mountain. Richard Holmgren is a Swedish archaeologist who led an expedition that followed in the footsteps of the Dyatlov group in 2019. His group has a different explanation for how these injuries occurred.

HOLMGREN: The goal was to get there at exactly the same time. And we wanted to set up shop there exactly that same night. We thought this might help us understand your situation. And after experiencing the region's harsh climate, his group came to one major conclusion. HOLMGREN: In my opinion, the katabatic scenario is the only theory that would explain all the steps. A katabatic wind is a powerful “downwind” that travels down a mountainside, rapidly gaining speed under the force of gravity, and can create hurricane-like conditions without warning. HOLMGREN: In a katabatic scenario, it goes very quickly from strong winds to uncontrollable strong winds.

It can change dramatically in seconds, it doesn't take long. If this scenario affected the Dyatlov hikers, the canvas tent would be at risk of tearing and would have to be evacuated immediately. HOLMGREN: It's a matter of seconds, so the natural procedure to follow in this case would be to disconnect very quickly. And with temperatures around -30 degrees Celsius, his equipment would have frozen. HOLMGREN: I know it myself, putting on a boot under these circumstances takes three to four minutes. One boot. In the katabatic wind scenario, no one from the Dyatlov group is seriously injured in the tent.

And these deaths from hypothermia are explained in the same way. The injuries occur in the ravine where the bodies were found. Remember, these bodies were found buried under about four meters of snow. They may have dug a shelter in the snow for shelter, which collapsed and crushed them. HOLMGREN: The compressed chests occurred when heavy snow fell on them. And it got heavier during the spring, during the thaw. The injuries could even be postmortem. When the bodies were found, they had been decomposing for months under a layer of crushing snow. On a frigid February night in 1959, nine experienced hikers dug a platform into a slope to pitch their tent.

Hours later, something suddenly happened that landed them in the unbearably cold without proper clothing. A plate avalanche or a katabatic wind are just two of many theories. And in reality they have many crossovers. The plate avalanche theory needs katabatic wind to explain the transfer of snow from the top of the slope. And the collapsed snow cave in the katabatic theory is explained by a layer of soft snow, the shelter they dug, sagging under a heavy slab. Both give compelling reasons for the Dyatlov group to abandon their tent and offer a plausible explanation for the mysterious injuries.

Ultimately, though, since there were no survivors, trying to explain why the hikers did the things they did ends up raising more questions than answers. GAUME: This is one of the most mysterious parts of the Dyatlov Pass incident. The behavior of the hikers after the incident, after what happened during this night, is probably what will never be explained.