The Dyatlov Pass Accident refers to a mysterious event that resulted in the death of nine ski hikers in the northern Ural mountains. The accident happened on the night of February 2, 1959 on the east shoulder of the mountain Kholat Syakhl (Холат Сяхл) (the Mansi name, meaning Mountain of the Dead). The mountain pass (N61°45'17", E59°27'46") where the accident happened had been named after the group's leader, Igor Dyatlov (Игорь Дятлов) - the Dyatlov pass (Перевал Дятлова).
The causes of the accident are still unknown. Neither the official inquest, nor attempts by unofficial enthusiastic investigations, have solved the mystery.
http://en.wikipedia.org/wiki/Dyatlov_pass_accidentAND -----
In 1959, nine experienced Russian cross-country skiers — seven men and two women, led by a man named Igor Dyatlov — headed to the Ural Mountains, to a slope called Kholat Syakhl (Mansi language for "Mountain of the Dead," ahem) for a rugged, wintry trek. On their way up, they are apparently hit by inclement weather and veer off course and decide to set up camp and wait it out. All is calm. All is fine and good. They even take pictures of camp, the scenery, each other. The weather is not so bad. They go to sleep.
Then, something happens. In the middle of the night all nine suddenly leap out of their tents as fast as possible, ripping them open from the inside (not even enough time to untie the doors) and race out into the sub-zero temps, without coats or boots or skis, most in their underwear, some even barefoot or with a single sock or boot. It is 30 degrees below zero, Celsius. A few make it as far as a kilometer and a half down the slope. All nine, as you might expect, quickly die.
And so it begins.
http://www.sfgate.com/columnists/morford/