Turns out it wasn't just bad wedding invitations that killed Susan Ross. In fact, it was the actress' complete lack of comedic chemistry with the Seinfeld cast that led to the death of George Costanza's fiancé. 
 
 Jason Alexander revealed the details surrounding Susan's untimely demise during a visit to the Howard Stern Show on Wednesday. When Stern steered the topic toward rumors that Alexander couldn't stand actress Heidi Swedberg, the actor was quick to clarify: "She's a terrific girl...I couldn't figure out how to play off of her." 
 
 Alexander explained that though he often had trouble finding the right comedic tone with Swedberg, his cast mates were hard pressed to believe him. It wasn't until Jerry Seinfeld and Julia Louis-Dreyfus performed extensive material with Swedberg in Season 7 that they took Alexander's concerns seriously. 
 
 "Julia actually said, 'I know, don't you want to just kill her?,'" Alexander said, which he says gave show runner Larry David the perfect plot line for his then-undecided season finale. Cut to the end of Season 7 and poor Susan dies after licking poison envelope glue. 
 
 Harsh? Maybe, but don't worry too much about Swedberg — she's living the dream life of an accomplished ukulele teacher. 
 
 UPDATE, June 4, 10:56 A.M. ET: Alexander issued a response that further clarifies his comments on the Howard Stern Show. 
 
 He writes that no one on the cast disliked Swedberg, and that it was his intention to defend her from rumors when he told the story on Wednesday's show. 
 
 He also clarified that when comments were made about killing off Susan, they were directed strictly toward the character and not toward Swedberg herself, who Alexander writes, "was generous and gracious and I am so mad at myself for retelling this story in any way that would diminish her." 
 
 He closes out his statement with an apology: "To Heidi, I personally apologize. You are a sweetheart. I actually launched into this on Stern to defend you. But this is why I'm not a lawyer. Now everybody, calm down and just enjoy the reruns and think, 'why did he think this wasn't working? This is great.'" 
 
 Hear Alexander's entire story in the clip below: ||||| Her acting clashed with her costars’ — not that there’s anything wrong with that. 
 
 “Seinfeld” star Jason Alexander has revealed in an interview that the hit sitcom’s cast decided to kill off his character’s unbearable fiancée because she was “f- -king impossible” to work with. 
 
 The actor, who played the hapless George Costanza, told Howard Stern that actress Heidi Swedberg was given the ax after co-stars Jerry Seinfeld and Julia Louis-Dreyfus both agreed she was not jibing with the cast. 
 
 “And Julia actually said, ‘Don’t you want to just kill her?’ And Larry [David, the series’ co-creator] went, ‘Kabang! Now we gotta kill her!’ ” Alexander recalled on the “Howard Stern Show” on Sirius XM Radio. 
 
 Swedberg’s character, Susan Ross, was famously killed off in an 1996 episode titled “The Invitations” — in which she dies after licking toxic wedding-invitation envelopes that had been bought by George on the cheap. 
 
 Alexander, currently starring on Broadway in Larry David’s play, “Fish in the Dark,” told Stern that Swedberg had been unable to master her own domain. 
 
 “She’s a terrific girl. I love her. I couldn’t figure out how to play off of her,” he said. “Her instincts for doing a scene — where the comedy was — and mine were always misfiring. And she would do something, and I would go, ‘OK, I see what she’s going to do, I’m going to adjust to her,’ and then I’d adjust, and she’d change.” 
 
 In the show, George had attempted to sabotage his nuptials by taking up smoking and asking for a prenup. He even went out for coffee with actress Marisa Tomei, who played herself on the show. 
 
 The last straw came when Seinfeld himself did a scene with Swedberg. “Finally, they do an episode where Elaine and Jerry have a lot of material with her,” Alexander recalled. 
 
 After that scene, Louis-Dreyfus and Seinfeld said, “You know what? It’s f- -king impossible. It’s impossible,” Alexander told Stern. 
 
 “Every time I tell this story, I cringe because Heidi is the sweetest,” he added. 
 
 “And Julia actually said, ‘I know, don’t you just want to just kill her?’” he said. “And Larry went, ‘Ka-bang! Now we got to kill her, we got to kill her!’” 
 
 Alexander later offered a long mea culpa via Twitter. 
 
 “I feel officially awful,” he wrote in a linked apology. 
 
 “To Heidi, I personally apologize. You are a sweetheart. I actually launched into this on Stern to defend you. But this is why I’m not a lawyer.” 
 
 Swedberg — who has found a calling as a ukulele player in Los Angeles — could not be reached for comment Thursday night.
– In Seinfeld's seventh season, George Costanza's fiancee, Susan, was killed by toxic glue on their wedding invitations—and the man who played Costanza has now revealed that the cast had plotted to have her killed. Jason Alexander told the Howard Stern Show yesterday that while Heidi Swedberg, who played Susan, is a "terrific girl," there was a serious lack of chemistry between her and other cast members, Mashable reports. "I couldn't figure out how to play off of her," Alexander explained. "Her instincts for doing a scene, where the comedy was, and mine were always misfiring." Alexander says he complained about Swedberg and discussed her character's fate at dinners with show co-creator Larry David and other cast members who were finding Susan scenes difficult, ABC reports. Julia Louis-Dreyfus said, "I know, don't you want to just kill her?' And Larry went, 'Kebang,'" Alexander recalled. "Every time I tell this story, I cringe. Heidi is the sweetest." After her character's cruel death, Swedberg had roles in shows like Bones and is now a ukulele teacher, reports ABC. In the same interview, Alexander said other actors up for the Costanza role included Chris Rock, Paul Shaffer, Steve Buscemi, and Danny DeVito, who was offered it but turned it down, reports Entertainment Weekly.