Nola, the northern white rhinoceros at the San Diego Zoo Safari Park, is now one of only four left on earth.
The Czech zoo in Dvur Kralove reports its 31-year-old female northern white rhino named Nabire died Monday evening due to a ruptured cyst.
Nabire was born in the zoo on Nov. 15, 1983 -- a rare case of the species being born in captivity.
The zoo's director Premysl Rabas called the death "a loss hard to describe."
He said "Nabire's death has brought another animal species close to complete extinction."
Of the four remaining in existence, three are in Kenya's Ol Pejeta Conservancy and one is at the San Diego Zoo Safari Park near Escondido.
In 2009, the Czech zoo moved four rhinos to Kenya hoping that the natural environment there would help them breed but that plan failed.
Earlier this year 41-year-old Nola had surgery after a growth caused her right hip to swell. San Diego Zoo Safari Park staff recently told the Los Angeles Times that Nola was cancer-free.
All four living northern white rhinos are non-reproductive.