A manatee has drowned after getting stuck in a pool service shaft, the owners of a zoo in Paris said Monday.

Barry the manatee, who was three years old, died August 11 in a zoo in Vincennes after getting stuck "in an underwater gallery between two parts of the pool that are usually closed by a door," Alexis Lécu, the scientific director of the park, told the Agence France-Presse (AFP).

The 660-pound animal was one of only two of the sea mammals at the Paris zoo.

A spokeswoman told The Guardian that the manatee "forced its way into the shaft where it got stuck."

Authorities are currently conducting an investigation on the incident, and are trying to figure out exactly what happened and whether the manatees' enclosure needs to be modified.

These gentle giants are currently a vulnerable species onthe IUCN Red List, with only a few thousand left in the world mostly as a result of hunting. The herbivorous mammals remain submerged in shallow water or just under the surface and need to come up every five minutes to breathe.

"There are certain parts of the pool where the animal can rest out of sight of the public," Lécu told the AFP.

Barry was born in captivity at the Danish zoo at Odense and had been in Vincennes since July 4. The sea cow was one of a number of animals in a European breeding plan for the species. Lécu says the manatee pool design had been approved by a body that supervises the breeding programs and exchanges of European zoos, and had been inspected on site in February before the zoo's reopening.

Adult manatees, which measure on average about 10 feet (three meters) and weigh up to 1,300 pounds (600 kg), can live to the age of 40. In the wild, they are found in shallow, slow-moving rivers and coastal areas, but are slow, near-surface swimmers, and many are killed and injured when hit by motorboats, according to National Geographic.