SOUTH BEND, Ind. - The Potawatomi Zoo is mourning the death of its Amur tiger, Glinda.

The tiger died during a procedure to figure out what was causing her mobility issues.

Glinda had been showing signs of a mobility issue over the past week.

After a necropsy, animal care staff discovered an inoperable mass attached to the lower part of her heart, which was near her spine and made mobility challenging.  

The mass also weakened Glinda's heart's ability to manage anesthesia during her procedure.

Glinda was a resident at the zoo for seven years alongside her three sisters.