Actor Cameron Boyce passed away at the age of 20 over the weekend, after suffering from an ongoing medical condition that caused a seizure in his sleep.

Boyce was best known for his work on Disney Channel's television show Jessie, the Descendants franchise and Grown Ups films. Celebrities that worked with him and fans of his work reacted to the news of his death on social media.

The cast of Jessie sent words of love to his family and shared some of their favorite memories. Skai Jackson shared a number of photos and videos on her Instagram Story and posted a heartfelt tribute to her account.

"I am at a loss for words," she wrote. "I never thought in a million years I would be writing this. Cam, you were one of a kind." She said that he gave the best hugs and was the "big brother I never had." Charles Esten, who played their father on the television show, sent out a number of tweets sharing his favorite memories of Boyce and how great of a person he was.

Descendants director Kenny Ortega wrote two posts on how Boyce was immeasurably talented and how his kindness was "overflowing." Grown Ups star Adam Sandler, who played his father in the films, wrote a message on Twitter expressing his sadness.

Fans and celebrities began writing tributes on Boyce's final Instagram post. Wizards of Waverly Place star Gregg Sulkin wrote a heartwarming tribute. "Over the past decade I’ve met many actors, but you always stood out," he wrote. "Yes, you were talented. But most importantly, you were kind. You were humble. You had a special spark. May that spark shine bright in heaven."

See reactions from Cameron Boyce's many friends, fans and co-stars, below.