Two employees were part of a crew performing a re-roofing job (TPO type roofing work) at night. The building was 22.7 feet high (at the highest elevation) and was a single-story warehouse-type building with two roof elevations. The employees were on the highest roof elevation when a rough terrain forklift with a material handling wooden box on the forks was used to remove debris from the roof. The box was raised to the roof and the two employees got in the box to get a ride back to the ground. While they were in the box, it became dislodged and fell to the ground. One employee sustained head and body trauma, while the second suffered a fractured wrist. Both were hospitalized.