On 4 October 2010, a retaining dam failed on one of the red mud ponds at the company's Ajka alumina factory, spilling 600,000–700,000 cubic metres of highly alkaline and corrosive (caustic) red mud arising as a residual product from the treatment of bauxite with sodium hydroxide. At least ten people died, and about 150 people were injured, in the nearby settlements of Kolontár and Devecser.