These photos are from an experiment conducted at Sandia National Laboratories. To test nuclear reactor containment buildings, an F-4D Phantom was slammed into a concrete wall at 480 mph. Henderson crews constructed the concrete target, which weighed 1,034,000 pounds. 5,000 psi concrete was poured into forms and reinforced with 1 7/8 inch rebar placed 7 inches on center. Originally classified this experiment has been featured nationally.