Explaining Brazil #45: How to recover from the Brumadinho dam collapse?

On January 25, an iron tailings dam near the town of Brumadinho, in the Southeastern state of Minas Gerais, spilled the equivalent of at least 12 hundred Olympic-sized pools of mud onto the surrounding region. – How did this happen? – Who is to blame? – What will be the lasting environmental consequences? – And, most importantly, how can we prevent this from happening again?