Two employees were moving raw materials on a rolling cart. As they pushed the cart, its front wheels came in contact with a concrete joint in the floor. The weight of the cart shifted to the front, causing the load to become unstable and tip forward. One of the employees tried to keep the load from falling and was struck by the top bundle of material. The employee was caught between the bundle and other material stacked near the cart, suffering a fractured pelvis and tailbone.