An employee had just finished blasting several parts in the blast booth. He began to use compressed air to blow the steel shot media off two drive rings (brake housings weighing 1,114 pounds) that were on separate pallets 45 inches apart. He heard a cracking sound and turned as the drive ring behind him fell over, hit the small of his back, and landed on his left leg and foot. The employee sustained fractures to their tibia, fibula, ankle, and foot.