Abstract: At approximately 11:00 a.m. Employee #1, a construction worker, fell 21-feet and 5-inches while working on the leading edge of a roof. Employee #1 sustained a fractured pelvis, received a head contusion and a wrist injury in the fall. Six employees were working in a crew to install roof decking on a system engineered building. The roof decking process included the installation of a roll of insulation followed by two rows of roof decking on top of the insulation. Employee #1 was kneeling on the decking at the leading edge when he fell approximately 21-feet and 5-inches to the concrete floor below. Injuries included a fractured pelvis, head contusion and a wrist injury. Some evidence indicated that snow had been stuck on the Employee #1 knees which may have contributed to the fall. The building was approximately 290-feet-long and 180-feet-wide with a maximum height of approximately 21-feet and 8-inches at its peak. A controlled decking zone had been erected and trained employees were working in that zone. The weather was very cold; with temperatures around 10 degrees and light snow had fallen that morning.