Hearn was responsible for overseeing the quality and safety of the work. The buildings had to physically appear to be bombed, yet be structurally so they're safe for people. For instance, one of the two-story buildings appears to have a sidewalk on the second floor supported by columns. Otherwise, if a tank swung around the hit real columns, the sidewalk would collapse. Barry Stanfield, with Ware Energy in Louisville, Ky., which created the pyrotechnics and developed the computer system to control the action, took engineers and Fort Knox officials to Las Vegas to study the reenactment battles that occur on a pirate ship in a casino.
Propane gas is used to create the flame effects.
The engineers were originally considering using liquid propane. When you get involved in using fire around an audience, strong national codes have to be followed. Once we drew up the computer program that controls the fire effects, the Army follows it explicitly, for the liability on this is so great. The amount of time troops spend at the complex varies. Many of the groups do night training at the city, which is always open.