An 8-year-old Missouri girl who died suddenly after falling ill on a flight to Chicago in June was suffering from at least five different illnesses at the time of her death, a new medical examiner’s report found.

Sydney Weston died June 13 from complications of chronic primary adrenalitis coupled with several infections, including enterovirus and strep, according to Peoria County Coroner Jamie Harwood.

She was also suffering from inflammation of the small intestines known as duodenitis and the thyroid gland inflammation commonly known as thyroiditis, according to 25 News Now.

The long list of conditions suggested Weston may have suffered from an autoimmune disorder which left her body attacking its own healthy cells and harming organ operation, Harwood found.

Sydney died on June 13 after she became unresponsive while flying with her parents from Joplin, Mo., to a vacation in the Windy City.

The plane was diverted to Peoria, Ill., for an emergency landing, but Sydney died after being rushed to a nearby hospital.

Results from a previously released preliminary autopsy were inconclusive but found that her body showed no signs of abuse, neglect or foul play.

Sydney was just a week away from celebrating her ninth birthday when she died.

“She will forever be remembered for the happiness she brought to every single person she encountered. Our hearts are heavy. She was our baby girl and we celebrate her beautiful life,” her obituary read.