Abstract: Employees #1, #2, and #3 were employed by a subcontractor hired to repair the vacuum breaker on a blowtank-accumulator. The peppermill personnel were responsible for completely purging the tank of all flammable and combustible vapors. The peppermill lab technician was assigned to take an atmospheric air sample of the tank--the normal procedure was to take an air sample only in the area where the work was to be done. After the air samples were taken, Employee #2 ignited an oxyacetylene torch. A small cut was made, followed by an explosion. Employee #1 was crushed to death by the falling steel stairway. Employee #2 was killed when he was blown over the side of the tank and fell 40 ft, landing on a piping system. Employee #3 was hospitalized for several days and released. The bottom portion of the accumulator tank was never tested for flammable vapors.