Abstract: Employee #5 was giving a training session about the water filter swimming pool system to maintenance Employees #1, #2, #3, and #4, (a manager), when a malfunction occurred in the filter system. The malfunction was probably caused by some sort of blockage in the return feed valve. Water pressure built up in the system, blowing the top off the filter tank. Employee #1's face was cut and his arm was broken. Employees #2, #3, #4, and #5 sustained bruises. Employees # 1 and #2 were taken to the hospital, where Employee #1 was admitted and Employee #2 was treated and released. Employees #3, #4 and #5 received first aid at the site.