The oil giant BP marked the one-year anniversary of the Deepwater Horizon rig explosion by filing a pair of lawsuits in an attempt to win back some of the money it has paid out after last year’s massive oil spill. The suits target Transocean, the owner of the Deepwater Horizon rig, and Cameron International, the company that made the blowout preventer that failed last year. BP said it filed the lawsuits “to ensure that all parties involved in the Macondo well are appropriately held accountable.”