Abstract: At approximately 9:00 a.m. on September 21, 2012, Employee #1 was working alone and cleaning a water tank. The tank was approximate 100 ft by 80 ft by 25 ft (max depth) with a vacuum. He cleaned the tank to enhance its water clarity, so the tank could be used for underwater filming. Employee #1 used SCUBA equipment to remove debris from the tank at a depth of 25 ft. Another employee, who was assigned as his diving buddy, left the area for approximately 10 minutes. The coworker arrived and noticed no bubbles at the surface of the tank from Employee #1's SCUBA. The coworker entered the tank to rescue Employee #1, but he had drowned.