Kelly Preston and John Travolta

John Travolta and Kelly Preston turned their focus to funeral arrangements for their 16-year-old son, Jett, following Monday's autopsy that showed he died from a "seizure," The Associated Press reports.

The death certificate said he was killed by a "seizure," but gave no other details, Glen Campbell, an assistant director of the Bahamian funeral home, told the AP. Authorities performed an autopsy Monday but didn't release the results.

The teenager's body was expected to be flown Wednesday to Ocala, Fla., where the family has a home, according to the AP. The family had no further comment on Monday, a rep for the actor told TVGuide.com.

During a press conference Monday, a Travolta family friend told Us that Jett's body would be cremated. A memorial has been set for Thursday, which Ocala's mayor says the town will help facilitate, E! reports.

Jett was found unconscious on the bathroom floor of the family's Grand Bahama island vacation home by his nanny, Jeff Kathrain, on Friday morning. The Royal Bahamas Police Department said Jett, who had a history of seizures, had likely hit his head on the bathtub.

Travolta and Preston have said Jett fell ill when he was 2 and was eventually diagnosed with Kawasaki Syndrome, which can cause heart disease. Preston attributed Jett's illness to household cleaners and fertilizers, leading her to create a detoxification program based on the teachings of Scientology founder L. Ron Hubbard.

To combat Jett's seizures, the Travoltas sought the "finest" medical care for their son, family attorney Mike Ossi told Entertainment Tonight, which included the hiring of two nannies, one of whom was Kathrain. Jett was also on anti-seizure medication for a few years, which eventually proved to be ineffective. The Travoltas stopped administering medication "based on the doctor's advice," Ossi said.

The autopsy was conducted by two specialists, including a U.S.-certified clinical pathologist, and was observed by the Travolta family doctor, who received clearance to attend the procedure, lawmaker Obie Wilchcombe said.

"We are heartbroken that our time with him was so brief. We will cherish the time we had with him for the rest of our lives," Travolta and Preston said in their first public statement on Sunday.