BROWNSVILLE, Texas, Jan. 7 (UPI) -- A chlorine leak killed three western lowland gorillas and critically injured a fourth at the Gladys Porter Zoo in Brownsville, a zoo official said Monday.
The leak was discovered near the gorilla exhibit early Sunday and night zookeepers were able to rescue eight other gorillas, spokeswoman Lisa Marie Gomez said. They received treatment Monday and were expected to recover.
Caesar, a 3-year-old ape, was on a ventilator and under sedation, Gomez said.
"Everyone here is devastated," she said. "The people who work with the gorillas can't even talk about it."
The two night zookeepers exposed themselves to the leaking chlorine when they entered the exhibit about 4:15 a.m. Sunday. "They inhaled it themselves but they will be OK," she said.
An internal investigation is under way to determine what caused the toxic gas to leak from a container, Gomez said. The chlorine is used for cleaning purposes at the zoo.
Emergency medical technicians were called to the zoo when the unconscious gorillas were discovered and they administered oxygen to some of the apes and zookeepers. An exhaust fan was also used to clear the area of the fumes.
The gorillas killed in the accident were Kayla, 11; her son, Makoko, 2, and Uzuri, a 2-year-old female.
The fire department reported larger gorillas kept at least one young gorilla out of rescue workers' reach during the incident, according to the Brownsville Herald.