Tailings dam failure

On January 25, 2019, the tailings dam at the Córrego do Feijão mine in Brumadinho, Brazil, failed and killed more than two hundred and fifty people. A tailings dam holds back the slurry left by ore processing, a mix of water and fine particles. When the dam gives way, that mix flows like a fluid instead of sliding like earth, and it travels fast and far. Hence the gap between a modest-looking structure and the scale of the human losses. Two features make the risk distinctive. The structure grows throughout the life of the mine, often by raising the embankment upstream, the cheapest technique and the one most exposed to liquefaction. And it outlives the mine, with no operator and no revenue to maintain it, so the liability runs with no known end. The loss stacks up property damage, mass liability, environmental harm and claims against directors. The mining sector's usual limits rarely cover all of it. Since then, underwriting has relied on the Global Industry Standard on Tailings Management of August 2020, which requires structures to be classified and an engineer of record to be named.