Abstract: Employee #1, of Majestic Marble and Tile, was laying tile on the fifth floor guard station of a building. After finishing that room, he started mixing mortar and setting up to continue working on another floor. Employee #1 went up and down the stairway between four and five times, carrying up his tools. During one of these trips, he caught sight of a room off to the side that looked different. The doors were open, and there were no warning signs on them. When Employee #1 stepped into the dark room he fell between 35 and 40 ft down a mechanical shaft to the fourth floor, landing on metal ducting. He sustained a broken right toe, a puncture wound to his left shin, a laceration on his forehead, and multiple abrasions. Employee #1 was taken to the UCSD Medical Center, where he was hospitalized for approximately two days.