Abstract: At approximately 10:45 p.m. on September 18, 2005. Employee #1 began to walk out toward the water knockout tank in the facility, which liquefies petroleum gas. The petroleum gas, which was primarily composed of propane, was stored in underground caverns. Before the gas was shipped off to users, it had to go through dehydration and water knockout systems to remove its moisture content. Consequently, workers at this facility had to routinely remove water from the water knockout tank present at this facility. Thus, Employee #1 manually opened a ball valve in order to allow water to move from the water knockout tank into an evaporator sump tank. Then, the standard procedure required closing manually the ball valve when the material, which was coming out under a pressure of up to 200 psi, changed from liquid water to propane gas. A loud noise was emitted when this changeover occurred. A visibly detectable cloud of propane began to form if the worker did not close this ball valve. For some reason, Employee #1 never closed this ball valve. Instead, she apparently opened a second nearby ball valve, which only made matters worse by increasing the escape of propane gas from the water knockout tank. The only other workers present at the site at that time were two employees in a remote control room. They heard the loud noise and saw the cloud of propane gas, which was forming and increasing in size at a rather rapid rate. They quickly attempted to shut down everything, which could be shut down through the computer systems in the control room. However, the ball valves, which allowed propane gas to escape from the water knockout tank, could only be closed manually, by being physically present under the water knockout tank. It became apparent to them, that there was no safe angle from which to approach the water knockout tank. The propane gas cloud was large and appeared to be spreading outward in all directions. A huge explosion and fireball occurred. The other employees were knocked to the ground by the force of the explosion, but were not burned. They got back up onto their feet and dialed emergency ambulance. Employee #1 was found in a badly burned condition in the evaporator sump tank located below and slightly West of the water knockout tank. Employee #1 was killed.