Susan was killed off on Seinfeld due to incompatibility between the actress and the main cast’s comedic style.

In the popular sitcom Seinfeld, the character Susan Ross, who was George Costanza’s fiancée, was killed off in the show’s seventh season. The decision to write her out of the show was not due to any personal issues with the actress, Heidi Swedberg, but rather because of a perceived lack of comedic chemistry between her and the rest of the cast.

The show’s creators, Larry David and Jerry Seinfeld, along with the other main cast members, felt that the comedic rhythm and timing were off when they were performing scenes with Swedberg. Jason Alexander, who played George, particularly struggled with this dynamic. Despite Swedberg being a talented actress, the creators decided that the best course of action for the show was to remove her character.

The decision was made to have Susan die from licking toxic wedding invitation envelopes, which was a plot twist that was both unexpected and darkly humorous, fitting the show’s unique style. This decision was met with mixed reactions from fans, but ultimately, it served the purpose of maintaining the show’s comedic integrity.