Jim Henson died on May 16, 1990. It was a shock, as he was busy producing new projects with Disney and seemed generally at the top of his game. The infection that killed him could have been treated if he had gone to a hospital earlier. But Henson wasn't particularly fond of doctors, in part due to his Christian Science upbringing.
In the weeks after Henson's untimely death, several memorials were held, and by November, CBS aired a special tribute to Henson, complete with celebrity guest stars, various documentary bits on Henson's early career, and clips from many of his projects (Sesame Street, The Dark Crystal, Timepiece, and even his early commercial work).
The special also answered a key question the public had, following Henson's death: What would happen to Kermit? Simple: Steve Whitmire, a longtime Henson collaborator, would perform the character. Sure, Kermit's voice wasn't quite the same, but Kermit as a muppet would continue, and that was the important part. As the special says, "That's the way the boss would want it." Enjoy:
Trivia note: This also happens to be one of the last performances by puppeteer Richard Hunt, who performed Scooter and Beaker, among others. Hunt died in 1992.