Abstract: This accident occurred in the sterilization area where two 45 ft long by 4 ft 10 in. wide by 6 ft 6 in. high sterilization units were situated side by side. The construction crews were replacing a door on the unloading end of unit #1, using a torch powered by MAPP (methylacetylene propadiene) gas. Grinding was also being done. A few seconds after the door on unit #2 was opened an explosion occurred at unit #2. Several employees were directly in front of or near the exploding unit. Other employees were at unit #1. Employees #1 through #7 sustained burns and/or other injuries. Employee #8 died. The fuel sources were ethylene oxide (ETO), MAPP, propane, and gasoline. The gasoline was in a small can and the propane was in a cylinder on a forklift. Neither is considered to have caused the explosion. A small leak was found between the MAPP cylinder and the regulator, but it was not considered to have been large enough to have caused the explosion. The explosion apparently was caused by the ETO that was still in unit #2 and which ignited when unit #2 was opened.