A boy toddler was mauled to death at the Pittsburgh Zoo & PPG Aquarium Sunday after he somehow fell into the African painted dog exhibit.

The toddler, who was about 3 years old, was with his mother when, at 11:48 a.m. EST, he fell about 14 feet from an observation deck. Eleven dogs jumped on the boy, and zookeepers attempted to scare them off by firing darts into the pack, an action that appeared to have little effect, according to the Pittsburgh Post-Gazette. In a statement, the zoo indicated, “[U]nfortunately, the dogs were in pack mentality and not responding.”

A Pittsburgh police officer shot and killed one dog that continued to act “aggressive,” the Post-Gazette reported.

African painted dogs -- aka African wild dogs, Cape hunting dogs, and spotted dogs -- hunt in packs in sub-Saharan Africa. Each is about the size of a domestic dog weighing between 37 and 80 pounds and standing from two to three feet tall.

Lycaon pictus, the animal’s Latin name, translates as “painted wolf,” according to National Geographic. In Africa, the dogs hunting large prey, such as antelopes and wildebeests, by cutting off the escape routes of fleeing animals. They are members of an endangered species.

“It’s clear that the dogs did attack the child, but whether he died of the attack or the fall has yet to be determined,” Barbara Baker, the CEO and president of the zoo, told the Associated Press.

The zoo was evacuated immediately after the incident, and investigation by zoo executives and the Pittsburgh Police Department are under way, ABC News reported.

“Visitors alerted the staff immediately, and they went into emergency response mode,” Baker said. “Unfortunately by the time [emergency medical technicians] were able to get to him, the boy had passed away … We’ve had the exhibit up since 2006 and have not had any issues with the dogs.”