Puppeteer John Henson, son of the late Muppets creator Jim Henson, has died at his home in Saugerties, New York at the age of 48. Cheryl Henson says her brother died of a “massive heart attack” on Friday, February 14, 2014 after he had been building an igloo in the snow with his daughter.

Henson followed in his father’s footsteps as a puppeteer, performing as Sweetums in several films, including Muppet Treasure Island and It’s a Very Merry Muppet Christmas Movie. Henson was a shareholder and board member of The Jim Henson Company.

His mother, Jane Henson, died in April 2013 at the age of 78. Jim Henson died in 1990 after a sudden illness.

John Henson is survived by his wife Gyongyi and two daughters, ages 10 and 15. (via ABC, AP)