An employee was setting up their equipment and tools for the day and was going to raise their tools via buckets from a stairwell roof access on the ninth floor. The employee attempted to open the roof access hatch from a ship ladder after the hatch failed to open automatically. Once the employee pushed open the access door, they stepped back on their left foot to get off the ladder. Their left foot slipped and they fell backward off the fifth rung of the ladder, landing on both feet and suffering a fractured left tibia and fibula.