In 1993, a group of seven hikers led by Lyudmila Korovina embarked on an expedition in the Khamar Daban mountain range in Siberia. Known as the “Khamar Daban Incident” or “Mountain Madness,” the hikers faced an unexplained tragedy. Despite thorough planning, the group went missing, and only one survivor, Valentina Utochenko, was found covered in blood a week later. According to Valya, the descent from the summit took a dark turn as some members suddenly bled from their faces and died. The survivors, including Valya, were later found, but the cause of the mysterious deaths remains unknown. Theories include nerve agents, contaminated water, or poisonous mushrooms, but no conclusive evidence has been found. The incident poses a perplexing mystery similar to the Dyatlov Pass Incident.
I think there was a microwave experiment conducted in secret. If the experiment went wrong it had unintended consequences, it might have led to the symptoms observed in the hikers. But it is also possible that the experiment was done on the hikers to see its consequences. The problem is that the absence of concrete evidence supporting this theory makes it highly speculative. Microwave experiments, especially harmful ones, would typically leave detectable traces. However, I am not sure they were searching for these kind of traces after the incident but this is one possible explanation that I support the most.
Nonetheless, the true cause of the Khamar Daban Incident remains unknown. Without credible evidence, any theory, including the microwave experiment hypothesis, remains conjecture.