Public outrage is growing against the decision by the Cincinnati zoo to shoot and kill a male gorilla Saturday when he grabbed and carried a 4-year-old boy who crawled through a barrier and fell inside the gorilla enclosure. A bunch of petitions on and users with the hashtag # JusticeForHarambe on Twitter are raging against the zoo, and also calling for the child’s parents to be punished.

An amateur video of the incident showed Harambe, the 400-pound western lowland gorilla — a critically endangered species — standing over the boy, then picking him and dragging him on the surface of the water in the moat, but not attacking the boy at any point. The incident lasted about 10 minutes and the zoo’s dangerous animal response team, which considered it a life-threatening situation, chose to shoot Harambe with a rifle. The child was then taken to a hospital with nonlife-threatening injuries.

Justifying the zoo’s handling of the affair, zoo Director Thane Maynard, said: “The child was not under attack but all sorts of things could happen. He certainly was at risk.”

He also explained that a tranquilizer could not be used in the situation since it takes time for the drug to affect the animal. Maynard added that while the zoo made the right choice, which saved the boy’s life, all employees were devastated at losing the rare species.

The boy’s family issued a statement Sunday that said: “We extend our heartfelt thanks for the quick action by the Cincinnati Zoo staff. We know that this was a very difficult decision for them, and that they are grieving the loss of their gorilla,” the New York Daily News reported.

However, the move has drawn severe criticism on social media platforms. There are already seven petitions on — with almost 100,000 signatures between them — most of which are asking for parents of the child to be charged with negligence. Two of those petitions also call for boycotting zoos and some call for punishing the zoo employees responsible for Harambe’s killing. There are also at least two Facebook pages with about 30,000 “likes” that are asking for “charges [to be] brought against those responsible.”

However, the more vociferous responses came on Twitter.

There were also some more extreme views.

Harambe, who turned 17 the day before he was killed, had been transferred from Gladys Porter Zoo in Brownsville, Texas. Its director, Jerry Stones, who raised Harambe since birth, told New York Daily News: “He was a special guy in my life. Harambe was my heart. It’s like losing a member of the family.”

Sharing his enclosure with two female gorillas, it was hoped Harambe would father more gorillas. At the time of the incident, the two females had left the enclosure when called by zoo attendants, while Harambe went over to the boy.

The zoo was open to public on Sunday, but the gorilla exhibit remains closed indefinitely.

The episode also brought to mind an incident from 30 years ago, when a 5-year-old had fallen into a gorilla enclosure in a zoo on Jersey island in the English Channel. A male gorilla called Jambo had protected Levan Merritt from other gorillas before the boy was rescued by zookeepers. During another incident 10 years later, Binti Jua, a female gorilla in the Brookfield Zoo outside Chicago, saved a 3-year-old who fell into her enclosure.

The western lowland gorilla, whose adult males are called silverbacks for the distinctive fur on their backs, is listed as a critically endangered species since 2007, and only about 100,000 individuals remain, according to an estimate by World Wide Fund for Nature. Most individuals of the species in the wild are thought to be in the forests of the Republic of Congo.