Paul Newman confessed in interviews towards the end of his life that this film was the only one he ever did for the money. He referred to it as "that volcano movie" and said that he and most of the cast knew it would be a bomb from day one. Many believe that part of his salary from this movie was used as seed money for a salad dressing business he was setting up with author A.E. Hotchner, with 100% of the profits, after taxes, going to educational and charitable organizations. Their company, Newman's Own, established in 1982, has raised over $260 million for charities all over the world, and continues to grow and prosper to this day.
William Holden was hospitalized for six days during production to treat his alcoholism after director James Goldstone convinced producer Irwin Allen that Holden was a danger to himself and others in the cast.
Steve McQueen was under contract to Irwin Allen. After refusing a part in "The Towering Inferno 2", that film was scrapped and Paul Newman was brought in to make this film. McQueen never made another film for Irwin Allen--he died shortly after passing on "The Towering Inferno 2".
The bridge sequence was filmed at MGM's Stage 30, also known as the Esther Williams stage, since it had a sub-floor tank used in her films. The bridge was 30 feet above the stage, with smoke bombs and light flashes used to simulate the lava. Doubles could not be used during filming.
The stars of this movie that were in previous disaster movies include Paul Newman and William Holden (The Towering Inferno), Red Buttons and Ernest Borgnine (The Poseidon Adventure), James Franciscus (Marooned, Concorde Affair '79), Veronica Hamel (Beyond the Poseidon Adventure), Burgess Meredith (The Hindenburg), and Jacqueline Bisset (Airport).
Producer Irwin Allen bought the rights to the Gordon Thomas and Max Morgan Witt book " The Day the World Ended " and totally changed it. Their book was a factual depiction of the Martinique earthquake of 1902.