54 stingrays have died at a suburban Chicago zoo after oxygen levels in their tank malfunctioned and plummeted, officials say.
Veterinary staff was not able to rescue the four southern stingrays and 50 cownose rays in the exhibit, according to the Chicago Zoological Society, which operates the Brookfield Zoo.
The zoo staff is trying to figure out what went wrong with the life support system, and the summer-long temporary exhibit will remain closed for the rest of the season. The Stingray Bay exhibit has been operating since 2007.
“We are devastated by the tragic loss of these animals,” said Bill Zeigler, senior vice president of animal programs for the Chicago Zoological Society, in a statement. “Our staff did everything possible to try and save the animals, but the situation could not be reversed.”