Stephen Hillenburg, the creator of the beloved Nickelodeon cartoon series SpongeBob SquarePants, has died, the television network said in a statement. He was 57.

Hillenburg died after a battle with ALS, a neurodegenerative disease that affects nerve cells in the brain and the spinal cord. He revealed that he had been diagnosed with the illness in March, 2017.

In a statement issued by Nickelodeon, the children’s channel praised Hillenburg for his “unique sense of humor” which “brought joy to generations of kids and families everywhere.”

💛 We are sad to share the news of the passing of Stephen Hillenburg, the creator of SpongeBob SquarePants. Today, we are observing a moment of silence to honor his life and work. 💛 — Nickelodeon (@Nickelodeon) November 27, 2018

The first episode of the cartoon debuted on May 1, 1999, and the series has aired nearly 250 episodes to date. The program’s zany humor appealed to both children and adults alike, with several notable SpongeBob moments even being retooled as internet memes.

Without #Spongebob, we wouldn't have been able to enjoy these memesRIP Stephen Hillenburg pic.twitter.com/0QBCr46fmX — philip lewis (@Phil_Lewis_) November 27, 2018

RIP Stephen Hillenburg, thank you for all the memes pic.twitter.com/SVn7KemEu2 — Anonymous (@YourAnonNews) November 27, 2018

Sad sad news, Stephen Hillenburg the genius creator of SpongeBob SquarePants has died at the age of 57, Nickelodeon has said. Last year he revealed that he'd been diagnosed with the neurodegenerative disease ALS #StephenHillenburg#SpongeBobSquarePantspic.twitter.com/YLjcl2qLmi — lizo mzimba (@lizo_mzimba) November 27, 2018

So my heart is in literal pieces right now. 💔 Stephen Hillenburg, creator of Spongebob Squarepants, passed away today at the age of 57. Spongebob was truly one of THE defining shows of my childhood. Thanks for the laughs Stephen. 💛 #Spongebobpic.twitter.com/IZqOEVqgn2 — Yoeri (@Yoeridesloovere) November 27, 2018

Think your friends would be interested? Share this story!