Two employees were unloading a flatbed trailer that contained steel gas pipes. Each pipe was 40 feet long and weighed 900 lbs. After the pipes were unstrapped, the first employee climbed onto the trailer and began removing the chocks that were keeping the pipes in position. The second employee was standing on the ground next to the trailer. After employee 1 removed the chocks that were holding the top pipes in place, one rolled free and fell onto employee 2, striking him in the chest and leg and causing a fractured femur, hip, and ankle.