A noted American ski mountaineer, Hilaree Nelson, is missing after apparently falling into a crevasse on Monday while attempting to ski down a peak in Nepal.

Also on Monday, an avalanche lower down the same mountain, Manaslu, killed at least one person and injured 14, some critically, on a separate expedition, according to Nepal’s tourism department.

On Monday morning, Ms. Nelson and her climbing and romantic partner, Jim Morrison, stood atop Manaslu, the world’s eighth-tallest peak.
“Summit success!” they shouted, crying, hugging and taking photos with their three Sherpa guides, who used a satellite phone to share the good news with Jiban Ghimire, owner of Shangri-La Nepal Trek, the outfitter that organized their expedition.