Abstract: At about 2:20 p.m. on November 23, 1990, Employee #1, vice president of Bosler Energy Systems, Inc., was finishing the installation and startup of a portable boiler to be used as a temporary replacement for a boiler operated by Pacific Northern Oil at Pier 91 in Seattle. The boiler, a 1951 Gabriel two-pass scotch marine dryback, serial #732, ruptured its furnace tube "adjacent to the furnace-to-rear-tube sheet joint." The boiler rear door was blown off as the boiler moved rapidly to the north. Employee #1, who was in the path of the boiler, was struck in the head by the boiler's leading end and carried with it. His legs were amputated as the boiler contacted two concrete filled steel posts protecting a fire hydrant in the parking lot. The boiler came to rest 1,109 feet from its origin. The official cause of Employee #1's death was listed as "fractures of the vault and base of the skull with brain lacerations and bilateral lower extremity amputations due to blunt impact to the head and extremities." No violation of a WISH standard contributed to this accident. According to the City of Seattle Chief Boiler Inspector, a routine hydrostatic test would not have necessarily have disclosed the significant metal thinning in the area of the failure.