The blowout preventer that was intended to shut off the flow of high-pressure oil and gas from the Macondo well in the Gulf of Mexico during the Deepwater Horizon explosion on April 20, 2010, failed to seal the well due to unrecognized pipe buckling, according to a new two-volume draft investigation report released last week by the U.S. Chemical Safety Board (CSB). The complete BOP failure scenario is detailed in a new 11-minute computer video animation by the CSB.