John Travolta is "heartbroken" after he tried in vain to save the life of his son Jett by administering emergency mouth-to-mouth resuscitation before paramedics arrived.

The 16-year-old passed away in the Bahamas on Friday after suffering a seizure at his family's holiday home at the Old Bahama Bay Hotel on Grand Bahama Island, according to family attorney Michael Ossi.

The actor rushed to the bathroom at the property and tried to resuscitate Jett after the teenager's nanny, Jeff Kathrein, discovered him lying on the floor on Friday morning

Ossi says, "He didn't want anything to happen to that boy, and he kept on trying to revive him. He did mouth-to-mouth until they had to physically remove John to take Jett to the hospital. He never dreamed of this - their relationship was so close. He always said 'I'm happy as long as my kids are happy'. He is heartbroken... To bury your son is the worst thing you can ever do."

Jett was the eldest of Travolta's two children with Kelly Preston. The actor and his wife also have a daughter, Ella Blue, who the actor broke the news to soon after the tragedy, according to family friend Michael McDermott.