Two of the Baton Rouge Zoo’s four giraffes died early Saturday, one that had been suffering from a chronic illness and the other after she was knocked down by another giraffe in a barn stall, zoo officials said.

A 24-year-old giraffe named Hope was receiving treatment for a chronic limp and could not stand Friday morning so was kept in the zoo’s barn for the day, zoo officials said.

Because of severe weather Friday, the staff decided to move all the giraffes into the barn for the night. The zoo’s staff gave Hope a stall to herself, moving another female giraffe into a stall with a male giraffe, but the male giraffe fatally injured the female.

Staff decided later on Saturday to euthanize Hope, whose condition had worsened, said Sam Winslow, the zoo’s general curator.

To give Hope privacy, the staff tried to move a 30-year-old female giraffe named Mopani into a stall with a male giraffe named Roan. When Mopani entered the stall, Roan knocked her down, causing injuries leading to Mopani’s death about 2 a.m. Saturday morning, according to zoo officials.

Winslow said staff could not see any visible injuries on Mopani. But, he said, she was unable to get back up after she was knocked down and died in the barn where staff was keeping an eye on her.

“They’re so high up, it can be difficult if they go down in an unnatural manner, if they slip and fall or get knocked down,” Winslow said.

Kaki Heiligenthal, a spokeswoman for BREC, which runs the zoo, said Mopani and Roan had previously shared a stall earlier on Friday without a problem.

“They typically got along very well,” Heiligenthal said, adding that they shared a yard at the zoo. “Their keepers never would have put them in the stall together if they thought there was any chance of conflict.”

Heiligenthal said the keepers could not have stopped the fight.

“The act happened so quickly they couldn’t stop it,” she said.

Heiligenthal said the zoo strictly follows Association of Zoos and Aquariums guidelines, which have no rules against putting two giraffes together in one stall.

“It’s one of those things,” she said. “It just happens.”

Later Saturday morning, staff decided to euthanize Hope.

She had been suffering from a recurring front leg problem for the past eight years, Winslow said, and the staff had been giving her a form of pain medication. On Tuesday, she began limping on a rear leg, though, according to a news release issued by zoo officials. Staff thought she was improving until she was unable to stand Friday.

One of the two remaining giraffes at the zoo, Jewel, is Hope’s granddaughter.

“This is an extremely sad event for all of us,” zoo veterinarian Dr. Gordon Pirie said in a news release on the deaths of the two giraffes. “The death of any animal is always difficult, but to lose two in one day is just devastating.”

According to Winslow, both giraffes had been living at the zoo for more than 20 years.

“The staff is pretty upset about it,” Winslow said. “It’s been a pretty trying ordeal.”

Zoo Director Phil Frost asked the Association of Zoos and Aquariums to do an audit on the incident, including the review of all activities leading up to the deaths of both giraffes.

Results are pending in necropsies, the term for autopsies on animals, that are being performed by Dr. Fabrio Del Piero, pathologist with the LSU School of Veterinary Medicine.

The average lifespan for giraffes is 19.5 years.

The deaths of the two giraffes come five days after a baby golden lion tamarin born March 9 died Monday.

The furry golden lion tamarins, which are monkeys native to Brazil, are endangered, and BREC celebrated its birth as the first golden lion tamarin born there in the last six years. Zookeepers found it weak Monday and brought it to the zoo’s veterinary hospital that day, where it later died. More than 40 percent die within their first 30 days of life, the zoo said.

Follow Danielle Maddox Kinchen on Twitter, @Dani_Maddox4 .