The official death toll from a burst dam in the Brazilian town of Brumadinho has risen to 169, authorities in the state of Minas Gerais said on Monday.
A dam is a barrier that stops or restricts the flow of water or underground streams.
Reservoirs created by dams not only suppress floods. It also provides water for activities such as irrigation, human consumption, industrial use, aquaculture and navigability.
In addition, 141 people have yet to be located.
The dam, which held back mining byproducts, is owned by nickel and iron ore miner Vale SA.
About 200 residents were evacuated from an area near another tailings dam operated by Vale on Saturday, amid fears that it was structurally weak and could also collapse.