What could of happened to John Travolta's son

In this tragic story, more and more ideas are been thrown around about what could of possibly happened to John Travolta's sixteen year old son Jet when he passed away recently. Although the family claims its Kawasaki syndrome that caused the seizures, experts say that it is highly unlikely because only 1% of Kawasaki Syndrome sufferers have death as a direct cause of the syndrome and seizures are "very" unlikely. I feel for John and his family and I hope that they can somehow get closure on this drama. May you rest in peace Jet!