The Muppets family has just suffered a sudden loss. John Henson, son of Muppets creator Jim and his puppeteer wife Jane, has passed away. John, 48, was a board member on his late father's company and a puppeteer himself, most notably portraying and voicing the Muppet Sweetums. He reportedly died of a heart attack. He is survived by his wife, two children, and four siblings.

[via Deadline]