Mount Everest, French Tragedy. On September 9 at 7:30 P.M. an avalanche swept over and destroyed Camps I and II, killing the expedition leader, Gerard Devouassoux and five Sherpas. The expedition was abandoned after the accident. Base Camp had been established on August 25, Camp I at 19,000 feet (date unknown), Camp II at 21,000 feet on September 4 and Camp III at 22,650 feet on September 8. The French expedition, composed of Chamonix guides, was attempting a new route, heading directly to the west ridge from the shoulder above the Lho La, thus avoiding the Khumbu Icefall. Camps I and II were on the flanks of the shoulder and Camp III on the crest of the shoulder. Normal monsoon weather prevailed while the expedition was on the mountain. There was a fine period for three or four days before the accident, but for six days before that fine spell, from August 29 to September 3, there was continuous rain, snow and cloud across central and east Nepal. Since in central Nepal there was rain on September 10 and 11, this rainy period (and snow above 15,000 feet) may well have affected eastern Nepal on the 9th. This is normal monsoon weather. The monsoon normally does not finish until the end of September, unlike what the French seem to have thought. The International Himalayan Expedition to Everest in 1971 also considered a route to the west ridge via the shoulder, but it was immediately rejected when the very dangerous conditions from two prominent avalanche channels were realized.
Michael Cheney, Himalayan Club