It’s a sad day for zookeepers and the Honolulu Zoo’s sole remaining hippopotamus.

On Friday morning, Rosey, one of two female hippos, was found dead of unknown causes, according to a press release from Mayor Kirk Caldwell’s office.

A necropsy is scheduled for the hippo next week.

The hippo exhibit is closed indefinitely as Rosey’s body is removed.

Meanwhile, “zoologists will be monitoring and comforting the remaining hippopotamus during this traumatic time,” according to the press releasee.

Rosey was 3,000 pounds and 25-years old.