The High Court in London has ruled that BHP, the world’s biggest mining company, is legally liable for one of the worst environmental disasters in the history of Brazil. Hundreds of thousands of Brazilians, around 2,000 businesses, and dozens of local governments had sued BHP over the collapse of the Fundao dam in Mariana, in the southeast of the country, which was owned and operated by BHP and Vale’s Samarco joint venture. The event unleashed a wave of toxic sludge that killed 19 people and polluted the length of the Doce River. Judge Finola O’Farrell said in a summary of her ruling that BHP should not have continued to raise the height of the dam before its collapse, which was “a direct and immediate cause of collapse of the dam giving rise to fault-based liability on the part of BHP.”