Dueling-Stars Movie: They actually invented Diagonal Billing just for this movie, due to the star power of its leads Steve McQueen and Paul Newman, who were professional rivals at the time.
Enforced Method Acting: In a scene where a bunch of people are fighting to get onto an elevator, the extras were really fighting to keep off the elevator, since anyone who did get on it was pretty much done, and anyone who stayed off it was guaranteed a job for the next couple of months.
Hey, It's That Guy!: The chief of security is none other than OJ Simpson. Lisolette is Jennifer Jones. The fire chief is Steve McQueen.
And one of the chiefs filling Steve McQueen in on the plan to blow the water tanks is Dabney Coleman.
Science Marches On: Since the making of this film, there was the notorious MGM Grand Hotel fire when it was discovered and publicized once and for all that in a major structure fire, it's not the flames themselves that is the major killer, it's the smoke.
In the documentary film of the real events of Nine Eleven, a man in the street looks up at the World Trade Center burning and says "...this is just like The Towering Inferno, like in a movie."