An employee was stacking bales of plastic bottles weighing about 500 pounds. After stacking two bales, he moved his forklift back and got off it to pick up some metal strapping that was under a third bale. When he picked the strapping up, the two stacked bales tumbled down. They knocked the employee to the ground and then landed on his legs. He suffered a compound fracture to the left leg and a broken right lower leg.