Abstract: At approximately 4:15 p.m. on March 22, 2001, Employee #1, working as a truck driver, was making a delivery of crushed limestone powder to a floor tile manufacturer. The employee noticed a hissing sound coming from the second of four hatches on top of the truck (tank). The tank is pressurized by a compressor and blower to force material (limestone powder) from the tank into the plant's limestone silo. The hissing was believed to be caused by the hatch not being completely sealed, thus allowing a release of pressure from around the sides of the hatch. Employee #1 climbed up on top of the tank and attempted to stop the leak. While he was leaning over the hatch, there was an explosion and the hatch blew off the tank. Employee #1 was killed when the hatch struck him in the face and knocked him off the tank. The employee's body landed on a platform approximately forty feet from his truck. The safety (pressure release) valve on the compressor and blower malfunctioned preventing it from functioning properly causing the tank to pressurize.