Five years ago, the city of Mariana in the southeastern state of Minas Gerais was the stage of one of the worst environmental disasters ever recorded in Brazil. After an iron ore tailings dam collapsed in the town — some 65 kilometers from state capital Belo Horizonte — the equivalent of 25,000 Olympic swimming pools of toxic sludge was spilled, destroying entire towns and resulting in 19 deaths. It also devastated the Rio Doce, one of the region’s most important waterways. Thousands of animals were killed and experts at the time reckoned that it would take decades to reverse the catastrophic damage caused.
The tragedy was the result of a series of mistakes and negligence by Samarco, the mining company which owned the dam, as well as Brazilian public institutions that failed to enforce the country’s already-lax environmental legislation.