Abstract: At 7:30 a.m. on September 12, 2019, an employee, a field service technician, was accessing a roof hatch from an interior metal framed fixed ladder (15 rung) to perform maintenance on a rooftop HVAC system. The technician fell approximately fifteen feet from the fixed ladder and landed on the hard concrete surface below. The technician sustained fractured ribs, fractured vertebrae, and a blood clot in the brain. The injured technician was hospitalized for two weeks. The technician was working alone in a closed room at the time of the fall incident. The technician was not found by first responders until approximately 12:30 p.m. on September 12, 2019. The roof hatch was observed to be partially opened when first responders arrived to the fall scene. The roof hatch was equipped with hinges and locks that provided easy opening and closing. No work had been performed on the rooftop level prior to the fall incident occurring. The fixed ladder was maintained in a safe working condition. The technician was maintaining three points of contact when climbing the fixed ladder. The technician was trained on topics such as safe ladder use and fall protection. It was undetermined what caused the fall incident.