The actor said he still thinks of his son every day.

John Travolta has paid tribute to his late son Jett on his 30th birthday. Jett tragically died after hitting his head on a bathtub during a seizure on a family holiday in 2009. He was only 16 years old at the time. The actor took to Instagram to share a black and white photo of him with Jet, writing: "My dearest Jetty, I miss you more than words can say. I think about you everyday. Happy Birthday. Love, your Dad." John’s friends and family also shared sweet messages for Jett’s birthday in the comments, with his daughter Ella writing: "Happy Birthday Jetty, we love you so much." Jett had suffered from a number of health conditions in his life, which the family chose to keep private until after his death. He also had autism and Kawasaki Syndrome. Kawasaki Syndrome is a rare condition in children that causes swelling or inflammation in the walls of small to medium-sized blood vessels that carry blood throughout the body. John previously told Us Weekly that his son’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. Life was no longer interesting to me, so it took a lot to get me better." John shared Jett with his late wife Kelly Preston - who passed away from breast cancer  in 2020 at the age of 57. They two are also parents to son called Ben daughter Ella. Jett's 30th birthday comes less than three months before the second anniversary of his mum's death. After Jett’s death, John set up the Jett Travolta Foundation in his memory - a nonprofit organisation to help children with special needs.