The killing of an endangered gorilla after a 3-year-old boy entered its closure at the Cincinnati Zoo over the weekend has prompted outrage among animal rights activists.

Outside the Philadelphia Zoo on Tuesday – where five Western lowland gorillas reside in a more than 10,000-square-foot area, and have steel pathways that allow them to travel over zoo visitors – some visitors said zookeepers acted appropriately to protect the child. 

“Gorillas move very quickly. I think they should have used a tranquilizer gun, but they made a split-second decision,” said Jack Norman, who was visiting the zoo from New Jersey.

“These are wild animals and if you let children near them, youneed to have your i’s dotted and your t’s crossed," he said.

Others were outraged by the news of the Cincinnatti Zoo killing Harambe, a 17-year-old silverback Western lowland gorilla – a subspecies that is currently listed as “critically endangered” in the wild – to protect the boy.

“For them to take that action and kill that gorilla, which is going extinct?” asked Dubbiel “Midas” Sowell, 23. “It was completely inappropriate.” 

“It’s the parent’s fault. The responsibility [is] on the parent to not have your child fall into a 12-foot well,” Sowell said, adding that Harambe – caught on tape cradling the boy in one arm before he was shot – might not have even hurt the boy: “It’s instinctual for them to care for them.”

But Philadelphia Zoo chief operating officer Andrew Baker, the former curator of primates, said that Harambe was “displaying” the child and could easily have hurt him. 

“I think the child was a convenient prop for his display. Without meaning to harm the child, he was putting the child at very real risk,” Baker said. “When he charged that moat, that was not about the child, that was about him displaying. They’ll often grab whatever’s convenient and drag that along for their display.”

Gorillas at the Philly Zoo are primarily seen by visitors through thick glass, which allow views into their outdoors area or the smaller adjoining indoor cages. But there is a roughly 15-foot outdoor viewing point where a heavily-meshed fence, a land area and a moat separate the public from the gorillas. 

“I have a lot of confidence in our barrier. A kid is not going to be able to get through that,” Baker said.

Baker praised the Cincinnati Zoo and said that given the risk to the child’s life, they acted appropriately in shooting Harambe.

“This kind of situation, it goes beyond zoos into any environment where accidents can happen – it’s kind of any leader’s nightmare,” Baker said. “Anything that delayed protection for that child was going to significantly increase the risk of serious injury or even death.”

All zoo staff are drilled in various emergency situations, and while children are allowed to roam and explore the zoo, staff will quickly intervene if they notice a completely unattended child, he said.

“It’s hard enough to understand our own motivations and those of other people,” he said. “As soon as you start to try to interpret what’s going through an animal’s mind, that’s challenging.”