Abstract: On November 29, 2004, Employer #1 and his supervisor were working for an employer that assembled and installed air conditioning units in commercial buildings during construction. Employee #1 was installing piping for sprinklers in an air conditioning fan unit. Employee #1 was using an 8-ft A-frame double step ladder, with a 250-lb load capacity, Serial Number 4552, Model Number FD108. Employee #1 and his supervisor stated that this specific job was difficult because they normally installed the air conditioning equipment before walls and computer equipment was installed. In this case the computer system, approximately the size of a house hold refrigerator, was already installed, and could not be moved, making if difficult for Employee #1 to place the ladder in an optimal position to perform his work. Employee was moving and reaching to the side in an awkward position while on the ladder, when the ladder moved or slipped causing Employee #1 to fall 4 ft 9 in. Employee #1 was hospitalized and treated for fractured vertebrae and a collapsed lung. Employee #1 was a full time permanent employee of the employer.