Eight case studies of fires, flash fires and explosions involving hot work are reviewed. Each of these accidents occurred in the course of performing hot work on, or in the vicinity of, a vessel, container, or pipe. In most cases, the fuel's presence was not identified prior to the accident. Another feature of these case studies is that the accident occurred despite the fact that the hot work operators were familiar with the tools, procedures, and the equipment on which they were working. The casual factors of these accidents are identified and compared with the applicable safety standards to show how safe work practices could have prevented the accidents. The fundamental conclusion to be drawn from these eight case studies is this: if you fail to recognize a hazard, you cannot control it.