One of the world's last Sumatran rhinoceroses died Sunday at the Cincinnati Zoo, marking a "devastating blow" to her rapidly dwindling species, zoo officials said.

Suci, as she was known, hailed from the rarest of all rhino species. The Sumatran rhino numbers no more than a hundred animals in the wild, almost all of them on the Indonesian island of Sumatra (see map), and is possibly the most endangered large mammal on Earth.

Loss of habitat due to logging and palm oil agriculture, as well as poaching for its horn for use in traditional Asian medicines, have led to the animal's demise.

The Cincinnati Zoo was the first facility to successfully breed the critically endangered species in captivity. The zoo has been working with Indonesian organizations for 25 years in its efforts to bring the species back from the edge of extinction. (Read "Rhino Wars" in National Geographic magazine.)

After the death of Suci at age 10, only nine Sumatran rhinos are left in captivity worldwide. Sumatran rhinos in captivity live an average of 35 to 40 years, according to the World Wildlife Fund. (Read about Suci in a 2013 article in National Geographic magazine.)

The zoo had been treating Suci for hemochromatosis-a genetic disease that causes too much iron to accumulate in the body-for several months, but her condition rapidly deteriorated over the weekend. Suci's mother, Emi, died from the same illness in 2009.

"Suci was a symbol of hope for her entire species, one that is quickly losing ground in the wild, and her absence will leave a great hole in our hearts," said Terri Roth, director of the zoo's Lindner Center for Conservation and Research of Endangered Wildlife.

"The international community has a great challenge on its hands," she said. "If we don't act quickly, and boldly, the loss of this magnificent animal will be among the great tragedies of our time."

"This Is How Extinction Happens"

National Geographic photographer Joel Sartore, who had photographed the 10-year-old animal since she was a baby, called the news "heartbreaking."

"This is how extinction happens," he said. "The animal is down to so few that each loss is so devastating.

"The Cincinnati Zoo has done a fantastic job with keeping this species going with little to work with in terms of number of animals," said Sartore, who shot the above photo.

Sartore featured Suci in his Photo Ark project, which is built around photographing endangered species in zoos. (See more of Sartore's work: "Stunning Pictures: Ten of the Rarest Animals on Earth.")

He said that Suci's death shows that "you can't protect the animals from everything."

The photographer remembers Suci as a "charming animal" that was docile and good-natured.

"As long as the food held out," he said, "she was there for you."