The injured employee was on top of a rail car after completing a chemical transfer. After removing the stinger (25' measuring pole), he stepped onto the barrel of the rail car, and went to hand the stinger to a co-worker who was on a rail car on a separate track. The injured employee lost his balance and fell forward through the cage on top of the rail car. He struck the side of the adjacent rail car and landing on the ground. The fall distance was approximately 15 feet. The employee sustained a compression fracture in his spine and fractures to both heels.