England’s High Court of Justice on Friday ruled that Australia-based company BHP Mining was liable for the collapse of the Fundão Dam in Brazil over a decade ago—which caused the country’s worst environmental disaster—despite the company not owning the dam then.

In delivering the long-awaited decision, Justice Finola O’Farrell held that the collapse, which killed 19 individuals, was reasonably foreseeable and rejected the arguments from BHP’s defense team that the dam failure was a “sudden and unexpected” incident. The court had considered the evidence illustrating how, over a year before the catastrophic event in 2015, the dam had started exhibiting signs of distress, such as seepage and cracking, and that a proper stability analysis at the time would have revealed an unacceptably high risk of collapse. The ruling is especially monumental in light of its application of Brazilian environmental law by an English court.

The case’s very presence in a London court posed a major hurdle, as BHP had previously argued that the UK lawsuit was an “abuse of process” that duplicated Brazilian proceedings, a challenge that had successfully been overcome today.

In applying Brazilian law, Justice O’Farrell clarified that BHP’s existence fell under the scope of the definition of “polluter” under its strict liability regime, which is defined under Article 3, IV of the Brazilian Environmental Law. Article 14, paragraph 1 of the Law imposes responsibility regardless of fault. The English Court had adopted a broad and multifactorial test established by Brazilian jurisprudence, stating that a polluter also includes not only the direct operator, but those who “finance it, and those who benefit when others do it.” The English Court had referred to the subjective approach adopted in allocating responsibility, with the case law of the Superior Court of Justice in Brazil providing a guideline that it includes factors such as control over the activity, the creation of risk, financing the activity, and economic benefit from the activity.

This comprehensive approach sets a powerful precedent in holding multinational corporations accountable in their home jurisdictions for environmental disasters caused by overseas operations. BHP owns half of Samarco, the Brazilian company that operated the iron ore mine where the dam had ruptured back in 2015. The rupture resulted in massive amounts of mine waste pouring into the Doce River in southeastern Brazil, with estimates that it could fill 13,000 Olympic-size swimming pools.

The vast gravity of the event and its aftermath were disastrous, with a report generated by the Wilson Center reporting that biodiversity in the river was significantly affected, with 29,000 fish carcasses collected. This in turn negatively impacted the food chain, with birds dying from starvation since its primary food source had been affected. 80 percent of the native vegetation was destroyed and Brazilian prosecutors had measured the extensive socio-environmental damage as between 37.6 billion to 60.6 billion reais.

Prior to this landmark decision, a patchwork of legal proceedings had been conducted by federal prosecutors with top BHP executives being charged with homicide against 21 people, although this was later suspended.