The July 23 failure of the Xepian-Xe Nam Noy hydropower dam unleashed more than 130 billion gallons of water on rural villages in southern Laos, in Southeast Asia, devastating thousands of houses and businesses and displacing more than 6,000 people. As authorities scrambled to gather information in the wake of the disaster, scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, activated a new tool to help them assess the damage and get help to people in need.