Abstract: Employee #1, a superintendent for a site subcontractor, was standing on the top of the floor of an incomplete "pour in place" pump station, directing workers in preparation for pouring a concrete stairwell. The supervisor of another company (the site general contractor) was also working on the pump station's top floor, adjacent to a floor opening (approximately 9 ft 4 1/2 in. by 3 ft 10 in.) that had been temporarily covered with sheets of plywood over 2 by 4s. The supervisor called to Employee #1 and said he was having a problem with the work. When Employee #1 turned and walked toward the supervisor, he stepped on the temporary floor opening cover. The cover's plywood sections parted or opened and Employee #1 fell 32 ft onto the concrete floor of the pump station's wet well. He was killed. Both controlling and creating employers were cited for apparent violations of 1926.500(b)(1).