Abstract: At 8:45 a.m. on August 8, 2017, Employee #1, employed by a scaffold company, was working inside a portable water tank on a ship. His assignment was to erect a scaffold inside the water tank. He had been unable to fit through the tank's manhole entry while wearing an emergency retrieval harness, so he had removed the harness before entering. He was standing on a work platform inside the tank when he fell through an unprotected hole in the platform to a lower level steel deck, a fall height of approximately 17.5 feet. An emergency rescue was conducted, and Employee #1 was transported to the hospital. He was admitted and treated for a left leg fracture, a back injury, and a laceration to the back of his head.