A flash flood that tore through Nepal on Wednesday swept away homes, bridges, and other infrastructure, according to Himalayan geologists. The event bears striking similarities to the 2013 Kedarnath disaster, the scientists said. The catastrophe may have been triggered by an ice avalanche, rockfall, or debris flow that temporarily blocked a narrow valley before the natural dam burst. Seismic activity is also being investigated as a possible trigger. The scale and force of the deluge have renewed concerns over global warming, rapidly retreating glaciers, and the growing instability of the Himalayan region. Experts noted that rainfall is now increasingly being recorded at elevations of up to 4,000 metres, where precipitation earlier occurred largely as snow.