In 1974, an ambitious expedition led by Frenchman Gerard Devouassoux, the deputy mayor of Chamonix, set out to make a “complete” ascent of the mountain’s formidable West Ridge. Though first-ascent credit generally goes to Willie Unsoeld and Tom Hornbein for their 1963 climb, the two Americans had relied on several route variations: they hadn’t climbed the entire ridge to the summit. Devouassoux and 19 team members intended to “straighten the route out.” They arrived late in August, after, they hoped, the monsoons, which regularly deposited deep, unstable snow across the mountain’s flanks. They knew the weather would be a gamble, but they didn't count on losing. The monsoons kicked back in while the climbers were spread across three high camps. During the night of September 9, a large avalanche flushed over the tents, burying Devouassoux and five sherpas. They were never found in the debris. It was one of the worst single incidents ever recorded on the peak, and climbers avoided the West Ridge for the next five years.