Based on two novels: "The Tower" by Richard Martin Stern, and "The Glass Inferno" by Thomas N. Scortia and Frank M. Robinson. After the success of The Poseidon Adventure, disaster was hot property and Warner Brothers bought the rights to film "The Tower" for $390,000. Eight weeks later Irwin Allen (of 20th Century Fox) discovered "The Glass Inferno" and bought the rights for $400,000. To avoid two similar films competing at the box office the two studios joined forces and pooled their resources, each paying half the production costs. In return, 20th Century Fox got the US box office receipts and Warners the receipts from the rest of the world.
Scriptwriter Stirling Silliphant combined the two novels to create one screenplay. The combined three words that make up the titles of the two novels were combined to give the name of the film, and the name of the building that is on fire (The Glass Tower).
Screenwriter Stirling Silliphant took seven main figures from each novel and incorporated them into the screenplay, as well as the major climax of each novel: the lifeline rescue to an adjacent rooftop from "The Tower", and the exploding water tanks from "The Glass Inferno".
Irwin Allen originally wanted Steve McQueen to play the part of building architect Doug Roberts. McQueen however, fought for and got the role of fire chief O'Halloran. The role of Doug Roberts went to Paul Newman.
Paul Newman's and Steve McQueen's names are staggered in the opening credits, closing credits, and on the posters so that, depending on which way you read it (top to bottom or left to right), both appear to get top billing. This is known as "diagonal billing", This strategy was being worked on when Newman and McQueen almost co-starred together in Butch Cassidy and the Sundance Kid, but McQueen eventually dropped out of the project and was replaced by the lesser known Robert Redford.
Steve McQueen and Faye Dunaway left strict instructions that they should not be approached by visitors to the set. McQueen also refused to give any interviews. Paul Newman asked only that he not be "surprised".
Desperate to capture a truly surprised reaction from the cast, Irwin Allen actually fired a handgun into the ceiling without warning the actors, who were understandably "surprised". The trick worked and he got his shot.
In an interview given years after the film was released, writer Stirling Silliphant said that he always sat under a sprinkler system head when visiting a building. He said he did that because he learned it from a fireman he interviewed while researching this project.
Both novels were inspired by the construction of the World Trade Center in the early-1970s, and what could happen in fire in a skyscraper. In Richard Martin Stern's novel, "The Tower", the fictional 140-floor building was set next to the north tower of the World Trade Center. The climax of the novel was centered around a rescue mounted from the north tower of the World Trade Center.
During filming an actual fire broke out on one of the sets and Steve McQueen found himself briefly helping real firemen put it out. One of the firemen, not recognizing McQueen, said to the actor, "My wife is not going to believe this." To this McQueen replied, "Neither is mine."
The fancy "blinkenlights" computer which runs the Glass Tower is an IBM AN/FSQ-7 Combat Direction Central, built in 1954 to protect the US from Soviet bomber attack. About a dozen of them were installed around the US. Based on vacuum tube technology, the 'Q-7 in action took up the whole first floor of a "bomb-proof" concrete blockhouse, and generated as much raw heat as five single-family houses. The whole system became obsolete when missiles replaced manned bombers as the main threat. Components of decommissioned systems were sold for scrap and bought by film and television production companies who wanted futuristic looking computers, despite the fact they were built in the 1950s. The components used in this film were previously used in _The Time Tunnel (1966)_ and _Earth II (1971)_, and later used in Futureworld and Independence Day.
The building used in the film was a series of miniatures and matte paintings. Only sections of the building were actually constructed for the actors and stunt people to perform their scenes. Exterior shots of the building were of San Francisco's Hyatt Regency with an additional 50 stories of matte paintings added.
In the original script the role of the fire chief (known at the time as Mario Infantino) was considerably smaller. According to director John Guillermin, the role was offered to Ernest Borgnine with Steve McQueen playing the architect. McQueen later said, "If somebody of my caliber can play the architect, I'll play the fire chief," and Paul Newman was brought onto the project as the architect.
The HH-1N helicopters are in the original paint scheme used by NAS Lemoore's Search and Rescue Flight. Later on, they were painted Red and White. Up until the unit's disbandment in 2004, the Flight was still pointing out it was their helicopters used in the movie.
At first Irwin Allen did not want to use music at the first 5 minutes of the Helicopter Sequence. John Williams told Allen that he could come up with 5 minutes of music for the beginning. When Allen heard it, he agreed with Williams.
The First Interstate Tower in downtown Los Angeles was completed the same year this film was released (1974). 14 years later, in May of 1988, the FI Tower experienced a real-life fire which burned out 4 1/2 floors , ruined many floors above with smoke and floors below with water, and closed the building for almost five months. The fire happened late at night, when only a few dozen people were in the building, and no crowds, traffic or other demands on water hampered firefighters. Only one death occurred, when someone used an over-ride key to force an elevator to the floor where the fire had started, and perished much as was shown happening to elevator riders in the film. The Los Angeles Herald ran side-by-side photos of the actual fire and the fire from The Towering Inferno on its front page the following day. The story of the real fire was told in the TV film Fire: Trapped on the 37th Floor.
The upper 15 floors of The Glass Tower was built as a facade in the dirt parking lot of the 20th Century Fox Ranch in Malibu, California, including drapes for all the windows and an explosion hole at the outside elevator track. It remained standing in the same location for many years, even after the state of California bought the land and opened the ranch to the public.
Paul Newman later regretted his decision to co-star with 'Steve McQueen' (I) because of the rivalry between the two, created by Steve. As a result, the fireman role dominates over Newman's architect. Three contributing factors are 1) Both characters have the same number of lines (at McQueen's insistence); 2) McQueen's character doesn't appear until 43 minutes into the film. As a result, Newman had used almost half his lines before McQueen enters. And 3) the fire chief is the authoritative hero that outranks and captures center stage over all other characters. During filming, Newman was quoted as saying, "For the 1st time, I fell for the goddamn numbers. I did this turkey for a million and 10% of the gross, but it's the 1st and last time, I swear."
According to the actor/stuntman Ernie F. Orsatti, Faye Dunaway was often late to the set or didn't appear at all. This made some scenes impossible to film and caused other actors such as William Holden and Jennifer Jones to become quite upset. William Holden reportedly shoved Faye against the wall one day and threatened her. For the next month, she had a perfect attendance record.
James Franciscus and 'John Forsythe' were the original choices for Senator Gary Parker. However, it was felt that they too closely resembled then-Senator John Tunney and then-Governor Ronald Regan. Since one was a Democrat and the other a Republican, they decided that they wanted to leave politics out of it. They then elected to offer the role to Robert Vaughn, who did not resemble anyone political at the time.
According to Susan Flannery, 20th Century Fox refused Irwin Allen to direct all of The Towering Inferno. Irwin Allen Directed all the Action Sequences and John Guillerman was hired only to direct The Actors only for Non-Action sequences. There were a total of Four Film Units Shooting at the same time.