In Seinfeld’s seventh season finale, Susan Ross, who was George Costanza’s fiance, dies after being exposed to toxic glue while licking cheap wedding invitation envelopes. Seinfeld is in a rare class considering that the overall tone of the show bordered on dark to begin with, so Susan’s death could be seen as the natural progression of that tone. Even so, it was still shocking! It was also the last episode written by Larry David.

http://www.movieline.com/2011/01/a-brief-history-of-death-on-sitcoms.php?page=3

http://pancakedominion.files.wordpress.com/2009/02/seinfeld_s7e24.jpeg?w=332&h=291

I think Susan's death was very in keeping with the tone of the series in that no weapons were used and there was no bloodshed or visible wounds involved. Also there was the irony in the fact that Susan died in the midst of the preparations for what should have been the happiest day of her life, her wedding day.

I agree with Marvo301's comments about Susan's death being in tone with show. To me, the most interesting thing about Susan's death wasn't the death itself, but the reactions to her death. There wasn't the usual big expression of emotion or grief that we've come to expect from TV series.

As is the show, it was a very unique way for Susan to die. And you've got to admit, it was kind of funny. I haven't seen that episode in ages, but from what I remember Jerry, Kramer and Elaine are trying to console George when they learn that she's gone, but of course George isn't that upset. He's actually relieved. And I love how at the funeral, he really has no emotion at all. That's George for you!