Nearly a decade after Brazil’s catastrophic Samarco dam collapse, a U.K. court has ruled that global mining giant BHP is liable for the disaster, marking a major breakthrough for roughly 600,000 victims seeking compensation. The 2015 failure of the Fundão iron ore tailings dam in Minas Gerais killed 19 people, destroyed entire villages, and sent toxic sludge coursing through 400 miles of river systems before pouring into the Atlantic.

The ruling, delivered in London, represents one of the most consequential judicial decisions involving a multinational mining company. Claimants had long argued that BHP, as co-owner of Samarco alongside Vale, failed to ensure safe operations despite long-standing warnings over the dam’s structural weaknesses. Friday’s judgment found the company responsible for its role in the collapse, clearing the path for what could become a multibillion-dollar settlement.

Legal teams representing the victims described the decision as “historic,” noting that it is rare for environmental claims tied to operations abroad to succeed in U.K. courts. Many affected communities say domestic efforts in Brazil have been slow, fragmented, or insufficient, prompting victims to pursue accountability through international litigation.

For BHP, the ruling intensifies the financial and reputational consequences of the disaster. The company has already faced multiple lawsuits and cleanup obligations in Brazil but has denied wrongdoing, arguing that Samarco was operated independently under shared governance with Vale. The London court rejected that position, concluding that BHP bore clear responsibility for oversight failures.

Environmental groups say the collapse remains one of the worst industrial disasters in Latin American history, with long-term ecological damage still visible along the Rio Doce basin. Fishing communities, farmers, and displaced families continue to struggle with polluted land, disrupted livelihoods, and delayed reconstruction.

Compensation hearings are expected to follow, and analysts anticipate a settlement that could rival the world’s largest environmental payouts. The case is also expected to influence future claims against multinational companies for overseas operations, strengthening arguments that corporate accountability cannot stop at national borders.

For thousands of survivors who have waited years for justice, the ruling is a decisive step in a battle that has defined an entire region’s recovery.