Abstract: At 10:00 a.m. on June 20, 2017, a contract supervisor assisting in the draining of a decommissioned gas field that contained process tanks. The work activity was part of a hazardous materials cleanup operation as a result of another tank that had become over pressurized. As the supervisor was manually operating a valve to drain a tank line filled with a bleach solution and other residuals, a rupture occurred. The threaded head of the tank blew off and struck the supervisors chest on his left side, injuring his left arm and lung. He died as a result of his injuries. The incident investigation reported that a protective blast barrier wall was set up between the tank being emptied and where the employees were filling totes with the residual liquid that were inside the tanks. The valve the supervisor was operating was located next to the tank.