Abstract: At approximately 10:00 a.m. on July 23, 2004, Employee #1, a laborer, was standing on the roof of a two-story condominium building while trimming trees with a chain saw and using a leaf blower to blow the debris off the roof trim. Employee #1 had placed a 24-foot Type II Werner, Model D1224-2, aluminum extension ladder at the inside corner of the condo courtyard. While Employee #1 was on the roof, one of the residents asked the other workers who were on the ground to move the ladder because it was leaning on plastic rain gutters. One of the workers moved the ladder to another location. The homeowner recalled that the employees had been having trouble with the pulley hoist system on the ladder, but there didn't seem to be anything else wrong with the ladder. After positioning the ladder, one worker went partway up the ladder to take the leaf blower and the chain saw from Employee #1 and bring them down from the roof. Employee #1 then told the coworker that the ladder was backwards and asked him flip it over. The coworker flipped the ladder and then held the ladder for Employee #1 to climb down. The homeowner came over behind the coworker to help hold the other side of the ladder. As Employee #1 stepped onto the ladder from the roof, the ladder slipped and partially collapsed because the extension portion was not properly locked in place. Employee #1 fell approximately 20 feet from the roof to the concrete sidewalk and landed on his back. Employee #1 was transported to Mercy Hospital where he was hospitalized for treatment of fractured vertebrae.