(Beijing) -- One crack in a wall is all it would take for a dark gray oval that sits across 11 square kilometers of land to create a massive disaster.

Situated just to the west of Baotou, a city in the resource-rich region of Inner Mongolia, the mine dump for Baotou Iron and Steel Group (Baosteel) is enclosed by a concrete wall that stands 20 meters high. It is one of China's largest tailings pools, and contains roughly 180 million tons of metal waste powder.