The couple, along with 8-year-old daughter Ella Bleu, left the islands Monday night after the autopsy was complete and returned with their son's ashes to their home in Ocala, Fla.
Travolta's publicist has announced that a memorial service for Jett is being planned for Thursday, and the town is already preparing to help the family with whatever special arrangements they may need for the occasion.
"We're assuming they'll have a lot of friends and family coming in, we're not quite sure who, that will need help moving around town," Ocala Mayor Randy Ewers told E! News. "We have the police department available, and the sheriff's department is working with them."
Ewers said that some members of his staff have already been in contact with representatives of the Travolta family.
"We'll try to handle it as best we can to give the family their privacy during this difficult time. They're a great family, and it's really unfortunate that this happened."
On Tuesday, two pathologists, monitored by the Travolta family doctor, conducted an autopsy on Jett. While the results have not yet been—and possibly never will be—revealed, the teen's death certificate listed "seizure" as the cause of his death last Friday.
—Additional reporting by Whitney English
(Originally published Jan. 6, 2009 at 11:15 a.m PT.)