54 stingrays die at Chicago-area zoo when oxygen level drops

The Stingray Bay habitat at Brookfield Zoo is closed for the season after a malfunction caused a drop in oxygen levels in the water.

Staff managed to restore oxygen levels to the tank about 20 minutes later, but it came too late and all the rays died.

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. He says staff is devastated by the loss of the animals and worked hard to try and save the animals. The oblong-shaped pool is about 80-by-26 feet long and three feet deep, said Zeigler.

The Chicago Zoological Society has chose to close the exhibit, which has been at the zoo since 2007, for the rest of the summer.

The zoo is investigating the life support systems to find out the cause of the malfunction.

Four men were killed and at least 18 other people – including a 12-year-old boy – have been injured in shootings across Chicago since Friday night, police said.