Photo: Screenshot from the website of thepaper.cn

A tiger cub recently drowned in a pond at Shanghai Zoo, the Global Times learned from the zoo on Thursday.

The tragedy happened on January 9, when the zoo sent an adult female tiger and its four babies out of their cages for outdoor activities, the zoo said in a statement it published online on Thursday afternoon, hours after news of the incident started spreading on social media. 

The tigers were playing in an outdoor area for tigers and lions at the zoo, until three of the baby tigers suddenly jumped into a pond around 3 pm, which was probably because of a "stress reaction" to the many visitors, the zoo said.

The zoo immediately isolated the mother tiger and tried to save the drowning cubs, but only successfully rescued two of them, according to the statement.

"The two rescued cubs were in good condition," a staffer with the zoo told the Global Times on Thursday. He didn't mention the ages of the three tigers.

The zoo explained in its statement that the rescue work lasted for hours, but they failed to save one tiger cub as the pond is large (543.5 square meters) and deep (2 meters) and there is some thick mud inside it.

"We feel deeply sad about it," the zoo said, adding that it will learn from this and improve its emergency response plans.

The zoo released the tigers out of their cages that day, as outdoor activities are good for them, the zoo told The Paper earlier on Thursday.