At first, it looked like Harambe, a western lowland gorilla, was trying to help the boy, say bystanders. As the watching crowd grew larger and louder, the gorilla roughly dragged the child through a pool of shallow water.

“It was pure panic,” said eyewitness Brittany Nicely to the New York Times. In videos uploaded to Twitter and Facebook, visitors can be heard screaming and a woman yelling, “Mommy loves you! I’m right here!”

After about ten minutes, fearing for the boy’s life, zoo staff shot and killed Harambe. The boy was rushed to a nearby hospital, where he was treated for “serious, but non-life threatening injuries,” and released the same day.

CNN reports that witnesses had earlier overheard the boy saying he wanted to go into the water.

As news of the shooting spreads, many have responded with fury. “This beautiful gorilla lost his life because the boy’s parents did not keep their eye on him,” reads an online petition that calls for holding the parents responsible for the death. It had garnered over 130,000 signatures at time of writing.

Others criticize the zoo, saying that the enclosure barriers were inadequate, or that the gorilla’s life should have been spared. Animal rights activists are planning a Memorial Day vigil for Harambe.

But Thane Maynard, the zoo director, said in a statement on Facebook that tranquilizing the gorilla was “not an option.”

“Tranquilizers do not take effect for several minutes and the child was in imminent danger. On top of that, the impact from the dart could agitate the animal and cause the situation to get much worse,” he said.

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