NATIONWIDE -- Stephen Hillenburg, the creator of Nickelodeon's hit animated series Spongebob SquarePants, has died. He was 57.

Hillenburg died from ALS, or amyotrophic lateral sclerosis, according to reports. He announced last year that he had been diagnosed with the disease.

"We are sad to share the news of the passing of Stephen Hillenburg, the creator of SpongeBob SquarePants," Nickelodeon said in a statement posted on Twitter. "Today we are observing a moment of silence to honor his life and work."

SpongeBob SquarePants debuted on Nickelodeon in May 1999. The series has aired more than 250 episodes in its nearly two-decade run.

The series has spawned two feature films--2004's The SpongeBob SquarePants Movie and 2015's The SpongeBob Movie: Sponge Out of Water. 

Earlier this year, Hillenburg was honored with a special Daytime Creative Arts Emmy for his "contribution in the animation field."