Brumadinho dam collapse is the world’s worst since Mariana

Just three years after the 2015 Mariana dam collapse, Brazil is witnessing a similar tragedy happening only 150 kilometers away, in the small town of Brumadinho. An iron ore tailings dam collapsed—belonging to Brazil’s biggest mining company Vale—spilling 3 million cubic meters of waste, according to early estimations from the local fire brigade which are set to increase. This time, the disaster has been much deadlier. At least 37 people were killed and over 250 are reported missing.

In terms of the volume of tailings, the Brumadinho dam collapse is 16 times smaller than Mariana — but it doesn’t mean it wasn’t massive. The most recent dam collapse involving Vale is already in the infamous ranking of the world’s worst mining catastrophe in...