The explosion aboard the Deepwater Horizon was caused by a BP engineering error, says the firm's official report into the catastrophe . Although it is not due to be released for another ten days, the report says that an employee misread pressure data, giving the go-ahead to replace the drilling fluid with seawater. As a result of using the lighter liquid, natural gas shot up the pipeline and exploded on the rig, killing 11.
The 200-page report has been compiled by BP's head of safety and operations, Mark Bly, who finds both BP and Transocean jointly responsible for the disaster. Although BP initially tried to hold both Transocean, the firm operating the rig, and Halliburton, the contractor, responsible, the report reveals that Halliburton had in fact warned BP of a potential blowout. BP's two partners have both claimed in front of federal investigators that they were following BP's designs and directives on the rig.