John Travolta paid tribute to his late son Jett on what would have been his 28th birthday on Monday, April 13. The 66-year-old actor, along with wife Kelly Preston and daughter Ella Bleu Travolta shared social media posts in honor of Jet, who passed away in 2009. “Happy Birthday Jetty! We love you! ❤️,” John wrote alongside a black and white snapshot of him and his firstborn smiling at one another. Like her husband, Kelly posted a photo of herself hugging Jett, which she captioned: “Happy Birthday to our sweetest Jetty, we love you!! 💖.”

Meanwhile, Ella, 20, shared a picture of herself as a little girl with her famous parents and big brother, writing: “Happy Birthday to my brother Jett, I love you so much ❤️❤️❤️.”

Jett, who was autistic, died at age 16 after suffering a seizure during a family vacation in the Bahamas. Ahead of his birthday, Kelly marked National Autism Awareness Month in early April with a moving post about her late son. “I have a special place in my heart for those with autism and special needs. Sending love to some of my favorite people in the world,” the 57-year-old actress penned. “My son Jetty was one of the most playful and wonderful souls you’ve ever met. Love to all of you with autism and special needs around the world.”

In 2014, John told the BBC that Jett’s death was “the worst thing that’s ever happened” in his life. “The truth is, I didn’t know if I was going to make it,” he confessed. “Life was no longer interesting to me, so it took a lot to get me better.”

Less than two years after Jett’s passing, the Grease star and Kelly welcomed their third child, son Benjamin. John credits his young son with helping the family move forward following their tragic loss. “We certainly have bonded together,” John admitted during a 2016 interview on Good Morning America. “Certainly having little Ben has been a beautiful kind of glue for us to re-bond after a tremendous loss.”