According to a Florida autopsy report a 4-year-old boy who collapsed in June after riding a rocket simulator at Walt Disney World had a serious heart defect which caused his death.

The autopsy revealed that Daudi Bamuwamye, who was on vacation from Pennsylvania with his family, apparently suffered a cardiac arrhythmia due to an abnormality of the heart muscle that he probably had since birth.

Dr. Jan Garavaglia, the chief medical examiner for the district said that people with this condition are at risk for sudden death throughout their life due to abnormal electrical heart rhythms, and that risk could be increased under physical or emotionally stressful situations.

It appears that Daudi became rigid while riding Epcot’s Mission: SPACE, a technologically advanced attraction that uses spinning centrifugal force to create the sensation of a rocket launch.

Bamuwamye’s mother told investigators he was unresponsive by the end of the ride.

After determining there was no trauma to Bamuwamye’s body, and no malfunctions with the ride, Disney reopened the attraction the following morning.

Disney displays warning signs and audio recordings to discourage visitors from riding the attraction if they are pregnant or have heart conditions or back and neck problems