Skai Jackson honored her former Disney Channel co-star Cameron Boyce in a series of online posts Sunday, after the news the 20-year-old actor had died.
Jackson, 17, played Boyce's younger sister on "Jessie" from 2011 to 2015. She wrote to fans promising their "timeline will be flooded with pics and videos of this amazing human," before sharing memories of him through the years.
"Just be thankful for everything that you have," she advised fans in a teary Instagram Live video. "Just always tell people that you appreciate them. Always be nice to people, because it doesn't mean they'll always be here... Tomorrow isn't promised."
'So much more was on the way': Disney Channel star Cameron Boyce has died at 20
Jackson and Boyce were two of the four young children who starred on "Jessie." They were 9 and 12, respectively, when the Disney Channel sitcom first aired.
On her Instagram story, Jackson remembered him as "the funniest" and called him "forever my brother." She included photos with "Jessie" co-stars behind the scenes and on red carpets, plus an old video of Boyce singing The Jackson 5's "I'll Be There."
"I never thought in a million years I would be writing this," she captioned one post. "I am so happy that I got to spend almost everyday with you on set, you gave the best hugs. I wish I would have hugged you tighter when I saw you a couple of months ago. Thank you so much for being the big brother I never had."
Jackson also slammed online trolls who start fake rumors about celebrity deaths. In 2013, Boyce had to assure fans he was still alive after a hoax about him began to circulate.
"I'm not dead, I promise," he tweeted at the time.
"The dumb hoaxes and putting r.i.p. on someone's page is no joke," Jackson added in an Instagram Story comment. "Tomorrow isn't promised to anyone. Just stop! Make sure you tell someone you love them today."