Death of Stephen Hillenburg
Nickelodeon said on that day that Hillenburg died of ALS, a progressive neurodegenerative disease.
"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."
However, Nickelodeon themselves and showrunners Vincent Waller and Marc Ceccarelli have decided to keep the show running with the same crew on board (Waller explained that Hillenburg wanted to keep the show going via his Twitter), so SpongeBob SquarePants has not come to an end yet. In addition, a spin-off, entitled Kamp Koral: SpongeBob's Under Years, is in production, despite Hillenburg not seeing any spin-offs being made, leading to accusations that Nickelodeon purposefully waited for Hillenburg's death for the spin-off to happen, though both Waller and Tom Kenny (the voice actor for SpongeBob) confirmed that Hillenburg knew about it.