Abstract: On September 3, 2011 at 10:30 am, a team of employees, all Fire Fighters, were practicing with new heavy hydraulic tools (e.g. specialized chain saw and rebar cutter) and manual tools (sledge hammer) on the kennel walls approximately 5 feet. Six kennel walls were parallel to and spaced about 3 1/4 feet from each other. In the process, the west most kennel wall was pushed over in the east direction. The wall knocked into the adjacent kennel wall, causing that wall to fall over. A "domino effect" was created and the remaining walls fell over as they were hit. Employee #1, the Fire Captain/Safety Officer, who was overseeing the training standing between the 5th and 6th kennel walls was seriously injured when the wall knocked him over and pinned him. .Employee #1was hospitalized for approximately 11 weeks.