Abstract: At approximately 12:00 noon on September 7, 1995, Employee #1 was alone on the roof of cathode block room 136G, measuring for metal decking for service platform framework, west of and part of a new make-up air unit. On August 31, 1995, duct work and an old make-up air unit had been replaced with a new makeup air unit, leaving a 49 in. by 10 ft 3 1/2 in. roof opening, covered by plywood, metal sheeting, and plastic tarp for weather protection, to be replaced at a later date by permanent decking and sheeting. When measuring for service platform metal decking to be installed above the roof opening, Employee #1 stepped on the plastic tarp over the roof opening and fell through the approximately 36 in. by 48 in. section of the west end of the roof opening. He struck an American underhung 5 ton bridge crane and rail 8 ft 9 in. below, and then fell another 13 ft 10 in. to concrete floor. Employee #1 was found on the concrete floor 5 ft in front of a Wheelabrator with his foot through the wall opening to alert coworkers. The Alcoa ambulance responded and arrived at 12:25 p.m., finding Employee #1 conscious, alert, and breathing, but bleeding from his nose and right ear and with injuries to his left eye, right shoulder and upper arm, left wrist, and left lower back. At 12:42 p.m., Employee #1 was loaded onto a Warrick EMS ambulance and at 12:52 p.m., transported to St. Mary's Hospital in Evansville, IN. On September 13, 1995, Employee #1 died.