Healy Tibbitts Builders, Inc., is a marine construction company based in Aiea, Hawaii. Healy was performing work for the U.S. Navy in Pearl Harbor when a large buoy—which had been suspended by a crane being operated from a barge—fell and struck four Healy employees who were working on an adjacent barge. Following this incident, the Occupational Safety and Health Administration conducted an inspection and issued Healy a five-item, serious citation. The only item at issue on review is an alleged violation of the Occupational Safety and Health Act’s general duty clause, 29 U.S.C. § 654(a)(1), which the Secretary claims is based on the exposure of Healy’s employees “to a struck-by hazard when [they] worked under a load that was suspended by a crane . . . .” Following a hearing, Administrative Law Judge Patrick B. Augustine affirmed this item. Because we conclude that the general duty clause is preempted here by a provision of OSHA’s Cranes and Derricks in Construction standard, we reverse the judge and vacate this item.