Abstract: At approximately 8:30 a.m. on June 26, 2010, Employee #1 was changing four wheels on a recreational pontoon boat with a dual axle trailer. The pontoon boat measured approximately 42.5 ft in length, and the boat along with the trailer weighed 5650 lb. The owner of the boat and trailer provided Kobalt 12-ton bottle jacks and 3-ton jack stands together with 2 in. by 6 ft, 2 in. by 4 ft, and 2 in. by 12 ft lumber for the cribbing. The boat and trailer was positioned to have a set of wheels on the north side and south side of the dual axle trailer. The recreational boat measured approximately 3.5 ft beyond the trailer on each side. Employee #1 was under the boat and outside the trailer to reach the wheels. The south side wheels were removed and replaced one wheel at a time. On the north side, the wheels and lug nuts appeared to be rusty and Employee #1 had trouble lining up the replacement wheel. Employee #1 removed both wheels and asked the owner to jack up the trailer. The owner cranked the bottle jack up four levels. Employee #1 then asked for one more. After the last increase, the boat made a groaning sound. The owner yelled to Employee #1 to get out of the way. The boat and trailer twisted and moved off the cribbing on the north side, striking and trapping Employee #1. The owner tried to use a floor jack to lift the boat off Employee #1. Emergency medical services were summoned and transported him to a medical center where he was pronounced brain dead. Employee #1 passed away five days later.