BHP's Samarco dam collapsed — 19 dead, $30B in damages, warnings ignored

BHP is one of the world's largest mining companies, headquartered in Melbourne, Australia. In 2015, it owned 50% of Samarco, a joint venture with Vale that operated the Germano iron ore mine in Mariana, Minas Gerais, Brazil. On November 5, 2015, the Fundão tailings dam at the mine suffered a catastrophic failure, releasing 43.7 million cubic metres of toxic mining waste. The mudflow killed 19 people, destroyed 1,469 hectares of forest, and travelled 668 kilometres down the Doce River to the Atlantic Ocean.

The investigation found that the dam had construction and design flaws, and that warnings about its instability had been ignored. The dam had been raised beyond safe levels without proper engineering studies. In 2025, a UK High Court judge ruled that BHP was strictly liable for the disaster, stating that 'the risk of collapse of the dam was foreseeable' and that technical warnings were ignored. The judge cited serious negligence in how the dam was managed.

The financial consequences have been enormous. BHP and Vale signed a $30 billion compensation agreement with the Brazilian government in 2024. BHP separately settled a US class action for $50 million and faced a UK class action seeking up to $65 billion on behalf of hundreds of thousands of claimants. In August 2025, BHP and Vale offered $1.4 billion to settle the UK case. The disaster is considered Brazil's worst environmental catastrophe and one of the mining industry's most costly operational failures.