Very sad to report that Stephen Hillenburg, the creator of "SpongeBob SquarePants," has passed away at age 57.

Hillenburg died of complications from amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig's disease) at his home in Southern California, according to THR. He was diagnosed with the neurodegenerative disease in March 2017.

Nickelodeon announced his death in a tweet today: "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."

Among those remembering Hillenburg today was "The Incredibles" director Brad Bird, who tweeted, "I first discovered 'SpongeBob' through my sons, who were loudly singing along with the dopey & memorable theme song downstairs. I came down to see what the ruckus was about and ended up watching my first episode. Many laughs. Many thanks, Steve Hillenburg. May you Rest In Peace."

Hillenburg was a former marine biology teacher who went into animation. That combination led to the creation of the beloved Nickelodeon character who lives in a pineapple under the sea.

"SpongeBob SquarePants" premiered in May 1999 on Nickelodeon. The series, which has aired more than 250 episodes, has won multiple awards, including honors from the British Emmys, the Annies and ASCAP. Hillenburg was nominated nine times for an Emmy but never won.

There were two "SpongeBob" movies,  2004's "The SpongeBob SquarePants Movie" and  2015's "The SpongeBob Movie: Sponge Out of Water." It also inspired the Tony-winning "SpongeBob SquarePants: The Broadway Musical."

"Steve imbued SpongeBob SquarePants with a unique sense of humor and innocence that has brought joy to generations of kids and families everywhere," Nickelodeon said in a statement. "His utterly original characters and the world of Bikini Bottom will long stand as a reminder of the value of optimism, friendship and the limitless power of imagination."

RIP, and thanks for all the the krabby patties.