80s Trivia: What character famously died on Sesame Street?

If you grew up in the 80s (or 70s, 90s, 00s or today, for that matter), you watched Sesame Street.  The program has set the bar for everything that kids television should be.  It is fun, educational and humorous - for both the kid and the parent.

That being said, the show is also known to tackle some pretty heavy issues, including racism, AIDS (the South African version of the show features a character with HIV) and death.

Reflecting the death of this characters real-life actor, Sesame Street was forced to explain to Big Bird, and indeed, its entire children's audience, what death was and what happened to this character.  The resulting scene led to one of the most touching TV scenes in the past thirty years.  Off of Pocket Trivia: 80s Trivia -  What character famously died on Sesame Street?  Was it Maria, Gordon, Mr. Hooper or Dan?