An employee was using a crane to lift a 1,200 lb., 36" x 18" solid copper block that was chocked with a nylon strap. The strap was not centered. When the employee lifted the block approximately 3" from the pallet it was sitting on, the block pivoted, fell from the strap, and struck the employee on his right foot. His 1st, 2nd and 3rd metatarsal bones were fractured, requiring hospitalization and surgery.