The first two volumes of a long-delayed investigation of the BP Deepwater Horizon oil rig disaster in the Gulf of Mexico were released last week by the Chemical Safety & Hazard Investigation Board. These CSB publications focus primarily on the blowout preventer, which deployed correctly but could not stop the spill because of a buckled pipe. They say regulators and the oil industry do not require adequate preventer testing. In addition, U.S. offshore regulations fail to call for process safety management or hazard assessment techniques. The April 2010 accident killed 11 workers and leaked 5 million barrels of oil into the Gulf over more than three months. Shortly after the accident, Congress called for the CSB probe, which was one of several that examined the accident. CSB issued a draft investigation report in 2012 and said last week that several more volumes of its overall report remain incomplete. They are to include a discussion of regulatory oversight and comparison of U.S. offshore regulations with those of other countries.