Abstract: Employee #1 was one of the contract employees hired by Baker Commodities, Inc., which had hired Lawrence Cable Services, Inc., to install computer cable. The site supervisor was at ground level doing preparation work and Employee #1 was standing on a wooden extension ladder extended approximately 20 feet. He was standing at approximately the 10 foot level installing cable along the ceiling line. The ladder did not have a nonslip base and was resting on a concrete floor, leaning against an interior wall. Employee #1 was "jumping" the ladder when it slipped on the concrete flooring. He fell to ground, sustaining laceration, abrasions, and fractures to the patella (left).