Glacier Breaks, Unleashing a Monster Flash Flood in Himalayas Photo: Uncredited (AP) At least 20 people are dead and up to 125 still missing after a piece of a glacier in the Himalayas collapsed on Sunday, causing flash floods and destroying a dam in its path. Video footage shows a colossal rush of water and rocks roaring through a mountain valley in the northern Indian state of Uttarakhand after a portion of the Nanda Devi Glacier broke off into a nearby river. Advertisement Many of the casualties were workers at two hydropower plants in the region, and officials said as many as 35 people are still trapped in tunnels at one of the plants further downstream. Rescue crews are hard at work attempting to free those still trapped.