As a contrast to the darkly
massive exterior of the building, the interiors are plastered in light shades and, since the rooms richly vary in form and size the interior materials are relatively few and uniform.
Although the cores
of the World Trade Center towers were
built of closely spaced,
massive steel columns and beams, the fire stairs themselves were encased only by gypsum wallboard attached to metal studs: two 5 / 8 - inch - thick layers
of wallboard on the
exterior and one on the interior.
«Armed and Underground: Production Design» (7 mins., 1080i / 16x9) brings production designer Jon Gary Steele into the interview mix for an insider's view
of the film's carefully - aged sets (the industrial - site
exterior was a real location in Fontana, CA, but the
massive interior was
built on a soundstage), while «Crash Course: Stunts» (11 mins., 1080i / 16x9) taps stunt coordinator Lance Gilbert to tell, among other stories, the one about crawling around on the floor with his kids» Hot Wheels cars to plan the armoured - truck chase scene with Antal.