CHICAGO (CBS) — A 7-year-old girl who died while attending a cheerleading camp in northwest suburban Park Ridge suffered a rare congenital heart disease, an autopsy has revealed.

Katherine Babich fell ill on June 27 while at a cheerleading camp at Maine South High School, and died after she was taken to the hospital.

The Cook County Medical Examiner’s office said an autopsy determined she died of Ebstein anamoly, a rare congenital heart defect. According to the American Heart Association, Ebstein anamoly results in a malformed heart valve that does not close properly, and might allow blood to leak between the chambers of the right side of the heart.

Katherine was a second grader at Field Elementary School in Park Ridge.

“All of us at District 64 are saddened by the loss of one of our students, and extend our deepest sympathies to her family,” District 65 Superintendent Laurie Heinz said in a statement the day after Katherine’s death. “Kate is known as an inspired learner, a leader and a good friend to everyone in her class. … I know her classmates and Field staff will miss her dearly.”

It was not immediately clear if Katherine’s condition had been diagnosed before her death.