A “beloved” antelope choked to death on the plastic cap of a snack pouch over the weekend, a Tennessee zoo announced.

Lief, a 7-year-old sitatunga antelope, died Saturday, Brights Zoo said on Facebook. The animal choked on the cap of a squeezable fruit sauce pouch that the zoo said is not allowed on its grounds in Limestone, about 85 miles northeast of Knoxville.

A sitatunga antelope can live up to around 22 years in human care, according to the Smithsonian’s National Zoo. Lief “still had a lot of life to live,” Brights Zoo said.

“Some ask why we don’t allow squeezable pouches into the zoo. The reason is simple — the packaging is dangerous to our animals,” the zoo said on Facebook.

“If you look at these lids from an animal perspective it looks like food,” it continued.

The zoo searches bags, but “some people find ways to sneak these [pouches] in,” it said.

The zoo added that guests are more than welcome to enjoy their squeezable fruit sauce pouches and other snacks in their vehicles or at the designated picnic areas in the parking lots and later re-enter the zoo as many times as they want.

Commenters on the Facebook post expressed outrage that broken rules led to the death of an animal. Replying to one comment, the zoo said it doesn’t believe anyone will take responsibility for Lief’s death.

Another commenter wrote about having witnessed adults throwing human food and trash into animal enclosures, to which the zoo encouraged reporting such behavior.

“If we know when it happens we can get staff there immediately to remove the objects, and with a description of the guests we can help them quickly find the exit of the zoo,” the zoo wrote.

According to its website, Brights Zoo is private and family-owned. It houses some rare and endangered species, as well as “more common but exotic creatures.”

This article was originally published on NBCNews.com