On May 13, 1995, the British alpinist Alison Hargreaves became the first woman ever to conquer Everest without assistance and using an oxygen mask. She became the second person in history to reach the summit of Everest without assistance - the first was Reinhold Messner (1980).
The goal of Hargreaves was to climb alone on three highest peaks - Everest, K2 (Chogori) in Pakistan, and also Kanchenjunga. So, just three months after the conquest of Mount Everest, when climbing to the top of K2 Alison died. Climbing took more than 12 hours, odako day, which seemed at first sunny and beautiful, ended with clouds and winds flying about 140 miles an hour. That day on mountain K2 six mountaineers were lost.
Alison's dream of conquering the summit of K2 without any help remained only a dream - her body was never found.
https://www.nytimes.com/2018/03/14/obituaries/overlooked-alison-hargreaves.html?smid=tw-nytimes&smtyp=cur