Short answers, pulled from the story.
The Dyatlov Pass incident was the deaths of nine Soviet ski hikers in the northern Ural Mountains on the night of the 1st or the 2nd of February 1959. Six died of hypothermia and three died from severe physical trauma, and the exact cause was never conclusively settled at the time.
Igor Dyatlov, a 23-year-old radio engineering student at the Ural Polytechnical Institute, led the nine-person ski expedition. He assembled most of the group from fellow students at the institute, and did not survive the trip.
The hikers cut their way out of their tent from the inside, though the exact reason remains disputed among researchers. Leading theories include a slab avalanche pressing on the tent, a violent katabatic wind, and infrasound-induced panic, while Russian authorities officially attributed the deaths to an avalanche in July 2020.
On the 11th of July 2020, Andrey Kuryakov of the Ural Federal District Prosecutor-General's Office announced an avalanche as the official cause. He concluded it forced the group to flee their camp in low visibility with inadequate clothing before they died of hypothermia, and a 2021 study led by Alexander Puzrin and Johan Gaume supported that a slab avalanche could explain the group's injuries.
Six of the nine hikers died of hypothermia, while three suffered fatal physical trauma. Nikolai Thibeaux-Brignolles had major skull damage, and Lyudmila Dubinina and Semyon Zolotaryov had severe chest fractures, and four bodies recovered from a creek in May 1959 also had soft tissue damage to the head and face, including missing eyes, a missing tongue, and missing eyebrows.
Dyatlov Pass is in the northern Ural Mountains of the Russian SFSR, named in memory of the hiking group even though the deaths actually occurred about 1700 m away, on the eastern slope of Kholat Syakhl. A rock outcrop roughly 500 m from the actual campsite now serves as a memorial to the nine hikers.