Backlash over Shooting of Gorilla at U.S. Zoo

A public backlash intensified Monday after zookeepers killed a critically endangered gorilla holding a young boy who had fallen into its enclosure in a horrifying incident captured on video.

Harambe, a 17-year-old Western lowland silverback gorilla, was shot after the four-year-old crawled through a barrier and tumbled into the enclosure on Saturday.

Video footage shows the creature dragging the boy through a water-filled moat while onlookers scream.

At one point, the huge animal stops and appears to hold the child's hand before pulling him out of view.

While generally acknowledging that zookeepers had few options, critics slammed the zoo and the child's parents.

"The enclosure should have been surrounded by a secondary barrier to prevent this," People for the Ethical Treatment of Animals (PETA) wrote on Twitter.

"This tragedy is exactly why PETA urges families to stay away from any facility that displays animals as sideshows for humans to gawk at."

Zoo officials said they were heartbroken over the loss of Harambe, but had to make a rapid choice on how to rescue the boy.

"A child's life was in danger and a quick decision had to be made," Zoo Director Thane Maynard said in a statement.

"Tranquilizing the 450-pound gorilla was not an option. Tranquilizers do not take effect for several minutes and the child was in imminent danger."

The boy's name was not released, but his family issued a statement to US media offering their "heartfelt thanks" to the zoo.

"We know that this was a very difficult decision for them, and that they are grieving the loss of their gorilla," the statement said.

Still, angry animal lovers expressed outrage that the child had slipped into the enclosure.

By Monday afternoon, at least 13 petitions had been created on the change.org website demanding justice for the slain animal.

The boy's mother "did not give proper supervision. As a result her child fell into a gorilla enclosure at the Cincinnati Zoo resulting in the innocent living creature being euthanized," one petitioner alleges.

Others called for a Harambe memorial to be built, and for people to boycott the zoo.

On May 21, a suicidal man jumped into a lion enclosure at a zoo in the Chilean capital Santiago.

Zookeepers shot and killed two of the cats to save the man as he was being mauled.

Gorilla populations have plummeted in the face of relentless habitat destruction. Fewer than 175,000 remain in the wild.