Abstract: At 11:15 p.m. on April 10, 2017, Employee #1, employed by a plumbing/heating/air conditioning company, was performing preventive maintenance on rooftop air conditioning units at a commercial building. He was walking back and forth across the roof and performing his regular duties when he fell through a skylight and landed on a concrete floor, a fall height of 19 feet. Emergency services were called, and Employee #1 was transported to the hospital. He was admitted and treated for severe internal injuries, including a lacerated liver, a punctured lung, head trauma, and neck injuries. The subsequent investigation determined that Employee #1 had not been using any fall protection.