Abstract: Employee #1 was removing equipment from an old industrial building before it was demolished. Employee #1 had removed several floor meters on the second floor and decided to examine those at the other end of the building. A large 50 in. by 93 in. floor opening had been cut by a previous contractor during equipment removal approximately one year earlier. Employee #1 was walking through a 17 1/2 in. wide area that ran between a row of lockers and the unguarded floor opening when he lost his balance, fell 14 ft 3 in. through the floor opening, and landed on a concrete floor. He sustained severe head injuries and died at the hospital.