Abstract: At approximately 11:30 a.m. on September 19, 2012, Employee #1 was climbing and working on an 8 ft ladder to access the plenum space and perform work on ducts located approximately 10 ft above the floor in a hallway. Due to the positioning of the work on the ducts, and the location where the ladder was placed in the hallway, Employee #1 had to bend his body around the ceiling tile grids to avoid hitting them while ascending and descending the ladder. As he was descending the ladder, Employee #1 was bending around the ceiling tile grids and placed most of his weight on one side of the ladder, causing him to lose his balance. The ladder fell sideways and Employee #1 fell down to the floor, landing on his back. Employee #1 was transported to a local hospital for treatment of injuries including four fractured ribs, factures to the spine, and a head injury, and was hospitalized over night for treatment of injuries.