Five climbers have died on Mont Blanc—Europe’s highest peak—and another is missing, a mayor in the French Alps said. The climbers disappeared overnight as they were trying to reach the Aiguille d’Argentiere, which tops out around 3,900 metres. Mont Blanc, in addition to its primary peak, contains some 200 summits. Several mountaineers have died already this summer, and local officials say they fear people are coming to Mont Blanc ill prepared for the dangers. August is the height of the climbing season on Europe’s tallest mountain, where even in the warmest months fierce snowstorms can strike quickly.