Catastrophic flooding along the Nepal-China border on Wednesday killed hundreds of people in Nepal and Tibet, with hundreds more reported missing, including foreigners and pilgrims. Rescue teams searched for survivors as Earth scientists analyzed satellite imagery to determine the cause. Geomorphologists Kristen Cook and Dan Shugar reported that initial images from Nepal were obscured by clouds and dust, showing only that a part of a glacier had broken off from Langtang Lirung peak near the Tibet border. Clearer images from Thursday revealed that the bedrock beneath the glacier had collapsed, carrying a massive chunk of ice down and sending boulders and ice into the valley, leading to the floods.