Marine fossils discovered near the summit of Mount Everest reveal that the world’s highest mountain was once part of an ancient ocean floor before tectonic collisions lifted the Himalayas.

New Zealander Rob Hall, at the 28,000-foot mark of Everest's Southeast Ridge in 1994, led Jon Krakauer's team up in 1996. A storm claimed the lives of eight climbers, including Hall's, on that widely ...