Last Friday, a tailings dam collapsed at an iron ore mine in Brumadinho, Brazil, spilling out more than 3 billion gallons (12 billion liters) of red mud and debris. Click the image below to see the areas around the dam before and after its collapse.Homes, cars, buses and other structures were engulfed by the sludgy spill, and the region’s entire ecosystem is expected to be impacted by the contaminants in the tailings — which include waste rock and other residue left over after ore extraction. As of today, media sources are reporting at least 99 people have died and more than 270 are missing.