Rob Shumaker, the president of the Indianapolis Zoo, appeared to be holding back tears on Tuesday when he announced that a second African elephant had died at the zoo within a week.
Shumaker said an 8-year-old African elephant named Kalina died suddenly on Tuesday morning.
"We've had a really difficult day. We've lost two of our youngest African elephants within a week of each other," Shumaker said at a press conference Tuesday. "Our zoo family is devastated."
Kalina's death comes just one week after the zoo announced the passing of Nyah, a 6-year-old African elephant who died after "a short illness" on March 19. They were both born and raised at the Indianapolis Zoo.
Shumaker said both elephants had high levels of elephant endotheliotropic herpesvirus, or EEHV, which can cause fatal hemorrhagic disease in elephants, according to early tests.
"It is one of the most deadly viral infections in elephants worldwide but is most commonly found in Asian elephants," the zoo said in a press release. "It occurs in elephants in the wild as well as those in human care such as in sanctuaries and zoos. EEHV can strike without warning."
Zoo staff said there is no vaccine for EEHV and it is not preventable.
Young elephants are at the greatest risk for the "very aggressive disease," according to Shumaker.
"I'd like to make sure that you understand that the virus only affects elephants. It poses no risks to humans or any other animals," Shumaker said. "We do not know what caused this to become active in Nyah and Kalina so suddenly."
He said other elephants in the zoo's herd had not tested positive for the disease as of early Tuesday.
Elephants are known to live long lives, but they have considerably shorter life spans in captivity than they do in the wild.
A six-year study published in the journal Science in 2008 revealed that wild African elephants in Kenya's Amboseli National Park lived more than three times as long as their captive counterparts living in European zoos.
The researchers found obesity and mental stress to be likely factors to their untimely deaths.
ABC News' Morgan Winsor contributed to this report.