Abstract: At 7:00 a.m. on April 20, 2017, an employee and work crew were on the roof of a building, tearing off the existing roofing membrane. During work, the employee was walking from the south west section of the roof, when he stepped on a weakened portion of the roof substrate. The employee fell through the roof to the floor below, a distance of about 23 feet. Emergency services were contacted and, upon arrival, the employee was taken to a nearby hospital where he was hospitalized and received treatment for multiple contusions/bruises. The incident investigation reported that the roof had several weak spots as a result of water intrusion. Tarps had been positioned below the water intrusion areas to capture the water and to divert it away from shelves where materials were being stored. The employees fall was slowed by the tarp below before striking the floor below.