Five faillures one after the other.
BP Investigation Released: The Oil Spill Was Everybody's Fault | TPMMuckraker: BP today released the report of its own investigation into what caused the Deepwater Horizon to explode and leak millions of barrels of oil into the Gulf of Mexico. We're still digging through the 193-page report, which you can find here, along with the appendices and executive summary. But according to BP's quick-summary press release, the company found that everyone involved had a hand in the disaster.
BP and Transocean were wrong when they thought well integrity tests showed the well was secure; Transocean's crew didn't react the right way when gas began flooding up the casing; the cement in the well, designed by Halliburton, failed; and the blowout preventer, manufactured by Cameron International, failed.
BP found itself absolved of accusations that its very design of the well caused the disaster.
"Based on the report, it would appear unlikely that the well design contributed to the incident," BP executive Tony Hayward said.