Entertainment TV Kaley Cuoco Pays Tribute to 8 Simple Rules Costar John Ritter on 17th Anniversary of His Death John Ritter died of an aortic dissection in 2003 By Maria Pasquini Maria Pasquini Associate Editor, Human Interest - PEOPLE People Editorial Guidelines Published on September 11, 2020 03:57 PM Share Tweet Pin Email Kaley Cuoco and John Ritter. Photo: Albert L. Ortega/WireImage Kaley Cuoco is honoring her late friend John Ritter. Seventeen years after the television star died of an aortic dissection in 2003, his 8 Simple Rules costar reflected on the actor's enduring legacy. "Can't believe you have been gone 17 years," Cuoco, 34, who played the actor's daughter on the sitcom, wrote Friday alongside a smiling Instagram photograph of the pair. "Thank you for continuing to make me laugh every single day 💜💜 ." Martin Spanjers and Amy Davidson, who also played Ritter's children on the show, went on to share touching tributes of their own. "17 years ago we all lost John. Each year I can't believe it's been another one. A lot of people will ask me, 'What was John Ritter like?' - I will respond with something like: He was the greatest. The most kind, genuine, loving and yes - hilarious person," wrote Spanjers, 33, alongside a playful cast photo. "Whether you were a random fan approaching him or the head of ABC, he would show you the same respect and gratitude with his time... looking you in the eye, joyful and remaining incredibly present. He was a mensch," the actor added. Kaley Cuoco and John Ritter. L. Cohen/WireImage In memory of Ritter, Spanjers went on to share that he would be working to raise awareness about aortic dissection. "To honor John and all those that have been taken from us too soon, I am taking part in Aortic Dissection Awareness Week (Sept 19-26). I will be sharing more information as I learn more through this event/conference but I urge you to join and spread the word if you, your family or if you know someone who has been affected," he wrote. "Knowledge is power and we have to fight with it to save lives." "Could not have said it any better. I love you, John! And thank you for sharing this information, Martini😉♥️," Davidson, 40, wrote in her post, re-sharing the actor's message. Remembering the Stars We've Lost in 2020 Cuoco also reflected on Ritter's legacy earlier this year, in remembrance of the 15th anniversary of 8 Simple Rules' finale. The series premiered in 2002, and Ritter died after completing just three episodes of the second season. After a brief hiatus, the show returned with an hour-long episode, addressing the death of his character. 8 Simple Rules aired until 2005, following the conclusion of its third season. Kaley Cuoco and John Ritter. Chris Weeks/WireImage "With John passing away, that changed the whole course of that show," Cuoco told Yahoo Entertainment in April. "Even though I only spent a year with him, that changed the course of my personal life and my career. I knew I wanted to make people laugh forever after working with John. That year really changed me in every way." "Watching [John] with everybody was like a light. It was the happiest place to be," The Big Bang Theory alum added. "He taught me what it's like to be a leader, and to lead a show. He taught me a lot."