The area above 26,000ft is called “The Death Zone” due to the atmospheric pressure. The air is so thin that recovering the dead bodies is impossible so they are left where they died.
There have been many cases where people had to leave behind some people that were still alive due to low oxygen. Sergei and Francys Arsentiev met that fate. Two climbers heard Francys screaming for help on the side of a steep cliff. She was seperated from her husband. The climbers had to leave her behind or they would have died themselves.
Some were lucky enough to die in their sleep, while others suffered injuries from falls and died slowly from hypothermia.