Predictably, it depends on whom you ask. The major corporate players in the spill were BP, which leased the well, Transocean, which operated the rig, and
“„BP America president Lamar McKay stressed the failure of the blowout preventer owned by rig operator Transocean. “The systems are intended to fail-close and be fail-safe,” McKay said. “Sadly and for reasons we do not yet understand, in this case, they were not.”
“„But Transocean’s chief executive Steven Newman said the blowout preventers “were clearly not the root cause of the explosion” ….
“„“The one thing we know with certainty is that on the evening of April 20 there was a sudden, catastrophic failure of the cement, the casing, or both.”
“„Halliburton’s Tim Probert also tried to deflect blame. He said “we understand that the drilling contractor . . . proceeded to displace the riser with seawater prior to the planned placement of the final cement plug . . . “