The young polar bear's liver enzymes were determined to be extremely high, the zoo shared on their website Tuesday
Berlin's little polar bear is called Fritz
Credit: Tierpark Berlin/picture-alliance/dpa/AP

The Tierpark Zoo is mourning the loss of one of its own.

Fritz, a polar bear cub residing at the zoo in Berlin, died suddenly on Monday, the zoo said on its website Tuesday.

Reuters reports that the 4-month-old cub, who had been celebrated in Germany as an heir to beloved polar bear Knut, died of complications from a liver inflammation.

A message posted on the zoo’s website said an autopsy of the polar bear at the Leibniz Institute for Zoo and Wildlife Research has so far led to no further results than liver damage. The enzyme values ​​of the cub’s liver were extremely high, it said, adding more results are expected in the coming weeks.

“Our first goal is to find the cause of the sudden death of Fritz as soon as possible,” said a statement from zoo and animal park director Dr. Andreas Knieriem, translated from German.

Sadly, it seems Fritz’s mother was shaken by the loss.

“The ice-cold mother Tonja has been looking intensively for her Fritz yesterday and was very nervous,” said a quote from bärenkurator Dr. Florian Sicks translated from German. “Today she was much more relaxed.”