Abstract: At approximately 9:20 a.m. on August 19, 1991, Employees #1 through #3 were on an oil well drilling crew that was assigned to change the rubber seals in a Grant rotary drilling head. Employees #1 and #3 were at the rotary table on the rig platform when Employee #3 directed Employee #1 to remove the bushings. When Employee #2 removed the clamp, the steam pressure blew outward and up through the rotary table. Employees #1 through #3 suffered steam burns, and Employee #1 was hospitalized. Employee #2 had failed to open the two manual relief valves to bleed off internal steam pressure prior to starting the job. None of the employees was wearing the required personal protection equipment, nor was the tool pusher on the drilling rig supervising the operation, as was required by the written safe operating procedures.