Dolphin shows at the
Nea, a 4-year-old Atlantic bottlenose dolphin, was set to perform an afternoon show when the accident occurred, officials said.
Preliminary results of a necropsy indicated she sustained a fractured skull, according to a press release issued by the Chicago Zoological Society, which manages the zoo.
The incident happened just before the 1 p.m. show. Marine mammal staff heard a loud pop and responded immediately, officials said. The staff noticed that the female dolphin appeared injured and trainers jumped into the water and attempted to save her by performing CPR, officials said.
Veterinary staff arrived in less than 10 minutes to assist, but the dolphin remained unresponsive.
The "freak incident" was not witnessed by anyone but according to the necropsy officials believe that Nea sustained her fatal injuries when she accidentally collided with another dolphin, officials said. There was no indication that the other dolphin was injured.
Nea arrived at Brookfield Zoo a year ago with Tatum, a 7-year-old dolphin. Both dolphins had integrated "very well" with the other dolphins, officials said.
Shows were canceled for the day.