Mount Everest's spring climbing season hasn't yet hit its busiest stretch, but tragedy already has struck: Nepalese officials say at least 12 guides were killed in an avalanche this morning and another three are missing, reports AP, in what is believed to be Everest's deadliest day. The avalanche struck an area above the 19,000-foot base camp known as the "popcorn field" around 6:45am, reports the BBC. The Sherpa guides were reportedly setting ropes for climbers preparing to head for the summit.
CNN says about 50 people, most of them Sherpas, were hit by the avalanche in all, and a Nepal Tourism Ministry official says the 12 confirmed dead were recovered from under snow and ice. The worst recorded disaster on Everest had been a snowstorm on May 11, 1996, that caused the deaths of eight climbers and was described in the book Into Thin Air. Six Nepalese guides were killed in an avalanche in 1970. (More than 300 climbers are expected to try the ascent this spring, with new orders to collect trash for the return trip.)