Abstract: On April 19, 1985, Employee #1, a timekeeper, was working atop circular cooling tower C1 at the River Bend Nuclear Power Station in Fort Francisville, LA. He had been told to help laborers clean up the area by picking up boards and lodged lumber. Apparently he accidentally picked up a 4 by 8 3/4 ft plywood sheet that was covering a 3 1/2 by 6 1/2 ft opening in the floor. When he picked up the sheet he went through the opening and fell approximately 42 ft to the ground. Employee #1 was killed. The cover had not been sufficiently secured and Employee #1 had not been informed of the hazard associated with the floor opening prior to working in the area.