Abstract: On July 26, 2001, Employee #1 was assigned to prepare the new fire truck for readiness and a training session. He was filling the truck's water tank through the discharge valve on the truck. The water was from the domestic water supply. The tank was filled about half full (400 gallons). There was a child present that was trying to squirt water out of one of the hoses. The water was not spraying well, so Employee #1 increased the pressure by running up the rpm on the engine. He must have forgotten about the hose hooked up to the discharge valve. The pressure increased in the truck tank and the water exited the discharge valve and over pressurized the domestic water supply tank. The bottom of the domestic tank ruptured and the 500-gallon tank went airborne about 100 ft and came down on the cab of the fire engine. Employee #1 entered the cab to shut off the engine. While inside the cab, the weight of the tank collapsed the roof and crushed him. He was struck in the head by the collapsing roof. Emergency medical personnel were able to remove from the cap and he was transported to the hospital. At the hospital, he died from the traumatic head injuries sustained in the accident.