Abstract: At about 7:30 a.m. on June 16, 1987, Employee #1, a brick mason employed by Metropolitan Masonry, Beltsville, MD, installed a bearing brick on the left side of a wall opening at the end of a hall on the second floor of the Southern Middle School, Lothian, MD. At approximately 8:00 a.m., Employee #1 helped install a 30 in. by 4 in. by 9 ft 10 in. pre-cast concrete slab into the opening. The pre-cast slab, which weighed 1,120 lb, was put in place using clamps, pry bars, hydraulic jacks, wedges, and a come-along. While Employee #1 was checking the fitting, some of the mortar squeezed out from the bearing brick that he had installed, causing the slab to lose its grip on the wall and fall from the wall opening, striking Employee #1 on the back. He was hospitalized for his injuries. The fastenings and attachments necessary to properly fasten and anchor the slab in place had not been used.