The presidential commission investigating the April 20 explosion of the Deepwater Horizon oil rig in the Gulf of Mexico cited a misread test as one likely cause of the disaster.
J. Scott Applewhite/AP
Crewmen and company officials overseeing the Deepwater Horizon oil drilling operation in April misinterpreted a critical "negative pressure" test on the well. They thought it was a success – it was actually a failure. If recognized, it would have revealed the imminent danger of a blowout, reported the chief investigator of the presidential commission looking into the disaster.
The blowout of the Macondo well that killed 11 men and wreaked environmental havoc on the Gulf also hinged on the failure of the cementing of the well. That critical process was to have prevented gases from flowing up and around the drill well casing, said Fred Bartlit, chief counsel for the commission.
But there is no evidence so far to suggest that there was a conscious decision to sacrifice safety to save money, he said. Instead, the preliminary conclusion on the cause of the disaster cites a litany of problems, including: