Khamar-Daban, a mountain range in southern Siberia, in the Republic of Buryatia, Russia, was a popular tourist hiking spot.

[2] She was joined by six of her students: Aleksander "Sacha" Krysin, Tatyana Filipenko, Denis Shvachkin, Valentina "Valya" Utochenko, Viktoriya Zalesova and Timur Bapanov.

[3] The first two days of the hike turned out to have gone better than the group had planned, with them making good time up Retranslyator peak, however, on 4 August, as they were beginning their descent, they were hit with an unexpected rainstorm.

Korovina decided to make camp in an exposed location, with the group failing at an attempt to build a fire that night.

[4] According to Valentina Utochenko, the sole survivor, while descending down the mountain, at the altitude of 2,396 metres (7,861 ft),[5] Krysin, who was at the back of the group, started screaming.

[4] Utochenko ran down the mountain, set up a tent for the night under tree cover and fell asleep.

[4] An autopsy, carried out in Ulan-Ude,[1] concluded that Krysin, Filipenko, Bapanov, Zalesova and Shvachkin died of hypothermia,[10] and Korovina had a heart attack.

[4] Rescuers Valery Tatarnikov and Vladimir Zinov, who took part in the search operation for the bodies, claimed that it was impossible for the hikers to die of cold.

[11] Tourist Vladimir Borzenkov and member of the search operation Nikolai Fedorov suggested that the hikers went mad due to infrasounds.

[3] Yuri Golius, the leader of the search operation, blamed their deaths on Korovina's negligence, claiming she was starving her students, which caused them to have vitamin deficiency.

[6] The first explanation proposes that the hikers died in the exact way the autopsy report concluded they did: by succumbing to hypothermia after not being properly sheltered that night.

[10] Certain parts of Utochenko's story could have been unintentionally exaggerated by her, due to the fact that people who undergo a traumatic experience often misremember details of it.

This theory was deemed uncredible due to the Khamar-Daban mountain range being a public area with many people traveling through it during tourist season, making it an unlikely place and time for conducting secret experiments.