MARIANA, Brazil: Fresh evacuations were ordered Wednesday at the scene of Brazil’s deadly mine dam tragedy as the CEOs of the mining giants that own the operation made a joint visit. The executives’ visit to the Samarco iron ore mine in southeastern Brazil followed mounting pressure for answers to the November 5 disaster, which left at least six dead and 21 missing after mud mixed with mining waste poured from two tailings pond dams at the facility. “Our immediate priority is to understand the full extent of the consequences of the tailings dam breach and how we can provide further help,” said Andrew Mackenzie, CEO of Australia-based BHP Billiton, the world’s biggest mining company, and Murilo Ferreira, CEO of Brazil’s Vale, in a statement. Fears for the safety of a third dam prompted new evacuations while emergency services made repairs Wednesday. Some 631 people had already been forced from their homes in the accident.