Every studio in Hollywood turned down Ebbe Roe Smith's script. Producer Arnold Kopelson was getting to the stage of considering cable TV when Michael Douglas came across the script and pronounced it one of the best he'd ever read.
The movie was being shot on locations in Lynwood, California when the 1992 Los Angeles riots began. By April 30, the riots were sufficiently disruptive to force filming to stop early that day. Film crews produced more footage inside of Warner Brothers Studio in Burbank as the riots continued. By May 4, when the crew intended to resume in Pasadena, initial requests to do so were denied, causing delays. The tension around the riots something that the filmmakers deem to have an effect on the finished film
In the scene in which the drive-by car crashes, there is a mural of Christ on the wall. This same mural is also present in Colors (1988), also starring Robert Duvall as an LAPD cop, in the scene in which the police officer played by Sean Penn, spray paints a kid's face.
"London Bridge is Falling Down" is heard several times in the film. Prendergast (Robert Duvall) sings "London Bridge" with his wife (Tuesday Weld) on the telephone. The same tune is played by the snow globe that D-Fens buys on Wilshire. The lyrics to the song are "London Bridge is falling down, falling down", a reference to the movie's title. A bridge appears on the retirement cake of Det. Pendergrast then moments later, he punches Detective Lydecker (D.W. Moffett) who falls into the bridge. Prendergast also planned to retire to Lake Havasu, Arizona, where the old London Bridge was moved to in 1971. D-Fens also says to Nick The Nazi (Frederic Forrest) "I'll fall down". See quotes section for more details.
The Korean American Coalition protested the film for its treatment of minorities as well as the Korean grocer. Because of this and the boycott threats that followed, this movie was banned in South Korea.
Where D-Fens (Michael Douglas) buys the snow globe for his daughter was filmed next door to the exterior shot of the Kobra Kai school (when Daniel is having lunch with his mother) in The Karate Kid (1984).
Joel Schumacher envisioned his friend Michael Douglas in the lead role. However, Douglas planned to take a break from acting as he had just done two films back to back and desired to spend some time with his family. Douglas agreed to read the script after Schumacher's urging and declared it one of the best he had ever read, taking the role immediately. The presence of such a popular actor as the lead allowed the film to get a much higher budget. Douglas, believing the film to be important, agreed to take a much lower salary so the film could also have more money to be made.
The scene where D-Fens (Michael Douglas) shoots out the phone booth is the same shopping center where Kane & Dooley (Eugene Levy and John Candy respectively go to Bruno's gym called the Sport Pit in Armed and Dangerous (1986). That scene was filmed behind the Subway and Mikasa restaurants shown in this film so it doesn't look the same, but it's the same building.
The trivia items below may give away important plot points.
As Bill Foster gets closer to home, the weapons he acquires become more lethal as do the people from whom he acquires them; First, he acquires a bat from the store owner, then a butterfly knife from the gang member, minutes later an Uzi from the same gang members car and finally a rocket launcher from the skinhead.