EXCLUSIVE-Brazil's Vale knew deadly dam had heightened risk of collapse

Vale SA , the world's largest iron ore miner, knew last year that the dam in Brazil that collapsed in January and killed at least 165 people had a heightened risk of rupturing, according to an internal document seen by Reuters on Monday.

The report, dated Oct. 3, 2018, shows that Vale classified Dam 1 at the Córrego do Feijão mine in Brumadinho as being two times more likely to fail than the maximum level of risk tolerated under the company's own dam safety policy. Vale did not immediately respond to a request for comment.

The previously unreported document is the first evidence that Vale itself was concerned about the safety of the dam. It raises questions as to why an audit around the same time guaranteed the dam's stability and why the miner did not take precautions, such as moving a company canteen that was just downhill from the structure. ( Reporting by Stephen Eisenhammer Additional reporting Ernest Scheyder in Houston Editing by Brad Haynes and Rosalba O'Brien)