The U.S. Chemical Safety and Hazard Investigation Board blamed a July 28 accident at BP’s Texas City refinery that caused $30 million in damage and one worker injury on a maintenance contractor’s inadvertent use of a carbon steel elbow to replace an alloy steel elbow. The elbow failed about three months after installation, releasing hydrogen gas, which caught fire and burned for about two hours. The investigation found that BP had not informed the contractor that the two parts were not interchangeable.