Glass Tower

The Glass Tower is the fictional skyscraper featured in the 1974 Irwin Allen disaster film The Towering Inferno.

Interiors
The Glass Tower was designed by production illustrator Dan Goozee under the direction of the production designer William J. Creber. The largest of these was a 70 ft model built on the concrete floor of the man-made Sersen Lake at the Twentieth Century-Fox Ranch located in Malibu.

Irwin Allen Productions utilized a 340 ft cyclorama of the San Francisco skyline for the view outside the Promenade Room windows. This artwork was completed by set designer Gary Coakley. (The cyclorama was also utilised in the Paramount Pictures, Star Trek IV: The Voyage Home in 1986)

The view depicted from the Glass Tower would be one seen from a vantage point 1800 ft above the center of San Francisco looking across the bay towards Oakland. The lights, which appeared to twinkle, were made by punching small holes in the backing and placing small quartz lights behind them. Blinking lights, representing aircraft warning lights on radio antennae and high hills, were lighted with red Christmas tree decorative lights. Shimmer was created on the "bay" waterby cutting slightly curly slits in the backing and hanging silk strips behind the backing. The strips were back lit and activated by gently by air fans to give the illusion of wave movement.

The scenes involving the water tanks and the glass elevators were shot at Century City, California. The distinctive pill-shaped glass elevators were replicated on set after location shooting was filmed at the Hyatt Regency San Francisco in the Embarcadero Center. The top-floor restaurant set covered 11,000 square feet. The lowest level was six feet off the stage floor and the ceiling was 12 feet above that. Three sides of the set were backed by the cyclorama.

Exteriors
Real street-level scenes set in front of the fictional Glass Tower were filmed at San Francisco's Bank of America Building using both the exterior plaza and the bank's lower lobby area. 37.79194°N, -122.40389°W

The Glass Tower's upper lobby area, with its large 16-story-high atrium, was filmed at the Hyatt Regency Hotel in the Embarcadero Center. 37.79859°N, -122.39805°W

Fictional structure
In the film, the tower is a 138-story structure that is sheathed with large floor-to-ceiling gold-tinted windows; exterior columns are clad in gold-colored metal panels.

Offices occupy the building up to the 80th floor. Jim Duncan's (William Holden) office is on the 65th floor and Doug Roberts' (Paul Newman) office is on the 79th floor. Floors 81 to 120 are residential apartments (but only some are occupied at the time of the fire). The purpose of floors 121 to 134 is never stated in the film, although the kitchen galley is presumed to be on floor 134.

The 135th floor features a 300-person capacity Promenade Deck ballroom, which affords a view of San Francisco from a height of 550 m. Along with two internal express elevators, it is also serviced with three external scenic elevators.

Floors 136 to 138 consist of machine rooms for the elevators and six massive water tanks which together hold one million gallons of water. The roof has a helipad.

The fire initially started on the 81st floor after a electrical short occurred in storage room 81k, but also spreads quickly to other floors (65, 83, 87, 95, 110) due to faulty wiring.