The BHP Billiton annual meeting in Perth on November 19 will have focused on the share price "wipe-out" – however, questions must be asked about the responsibility of BHP and Vale in their Brazilian tailings dam disaster on November 5.

The town of Bento Rodrigues​ has been hardest hit – more than 600 people have lost their homes, at least 11 people have been killed and 15 are still missing. The muddy red sludge extends 440 kilometres downstream across two states, affecting 635 municipalities and leaving hundreds of thousands with their water supply interrupted and potentially polluted for generations – with significant implications for health and agriculture.

The exact cause of the burst dam is not known but it appears that state mining regulations are inadequate and mine owners BHP and Vale, and operator Samarco, have failed to live up to their due diligence responsibilities as outlined in the OECD guidelines for multinational enterprises.

The Minas Gerais state environmental prosecutor declared: "This is no accident. It is a mistake in operation and negligence in the monitoring." A 2013 assessment by the independent Brazilian organisation Instituto Pristino highlighted concerns about the integrity of the tailings dam and recommended against renewing the licence. That call appears to have been ignored.