The stunt where the wall falls on Buster Keaton was performed with an actual full-weight wall. Half the crew walked off the set rather than participate in a stunt that would have killed Keaton if he had been slightly off position. Keaton himself, told the previous day that his studio was being shut down, was so devastated that he didn't care if the wall crushed him or not.
The movie was originally meant to incorporate a large flood as the disaster that hits the town. However, due to a real Mississippi flood and bickering amongst the producers, the flood plot was changed to a "cyclone."
During the hurricane sequence, there is a scene that pays homage to Buster Keaton's childhood on the vaudeville stage. One brief moment has a table move in the wind, apparently animating the dummy and turning its head to face Keaton. Keaton is startled and runs. This is based on a real experience from when he was a kid and became fascinated with a dummy named Red Top, who belonged to ventriloquist Trovollo. The young Keaton had a "conversation" with the dummy and conspired to kidnap his new friend one night when the theater was empty. Trovollo, anticipating Keaton, slipped to his props offstage and when Keaton approached, brought Red Top to life, scaring Keaton out of the theater.
This and The General (1926) are generally considered by critics to be Buster Keaton's last great films. Shortly after these two were made, the independent-minded Keaton made the mistake of signing a contract with MGM, whose regimented ways clashed with his scrupulous perfectionism. Five years after MGM hired him, it dropped his contract and Keaton drifted into obscurity, complicated by a severe drinking problem, from which he didn't emerge for many years.
Marion Byron could not swim, so the scenes where her character is in the river with Buster Keaton were filmed with Buster's real-life sister Louise Keaton serving as Marion's stunt double. The two were both the same size - 4'11". The water was very cold and during a day of filming Buster and Louise consumed 4-5 glasses of French brandy to keep them warm.
The failure of the original copyright holder to renew the film's copyright resulted in it falling into public domain, meaning that virtually anyone could duplicate and sell a VHS/DVD copy of the film. Therefore, many of the versions of this film available on the market are either severely (and usually badly) edited and/or of extremely poor quality, having been duped from second- or third-generation (or more) copies of the film.