Abstract: At 11:45 p.m. on January 17, 2017, Employee #1, a firefighter in full PPE, was trying to advance a 1.75 inch fire hose from the second floor, inside a residential multi-story home that was on fire. While attempting to advance the fire hose, the employee was struck by an unknown object inside the home, causing his fire helmet to shift. Employee #1s MSA respirator became slightly dislodged off his face, allowing toxic smoke to enter his air way. The employee made an unsuccessful attempt in securing his air way, and found himself in need of an air supply. The employee relocated to a window in the rear of the residential home, but fell two stories out of the window and onto an air conditioning unit that was located at ground level, parallel to the home. Employee#1 sustained injuries to his ribs, as well as contusions, abrasions and fractures and was hospitalized.