Several dozen locals were working at tailings dam at BHP Billiton's co-owned Samarco mine in southern Brazil on the afternoon of November 15, 2015, when they felt a tremor.

The tremor at about 2pm lasted several seconds. It was enough to rattle windows and to knock objects off tables across the Germano complex at the Samarco mine which is a joint venture between BHP and Brazilian mining giant Vale.