First-time mother Nasha went into labor Saturday, but developed complications. Zookeepers intervened to successfully deliver the calf, who appeared to be healthy. They then moved the newborn to be with her mother and said the two were bonding.
But shortly after announcing the birth, giraffe keepers noticed the calf was in distress.
"We are heartbroken to announce that Nasha’s calf died shortly after our birth announcement earlier today after the calf was accidentally stepped on by her mother," the zoo wrote on its Facebook page.
"Our animal care team quickly intervened but were unsuccessful at saving the calf," keepers said. "An initial necropsy showed trauma to the neck but further testing will follow to determine if there were any underlying causes for the newborn’s death."
Nasha's pregnancy was followed online by thousands of people around the world after a local TV station installed three live cameras in the giraffe's enclosure.
"We are devastated over the loss of Nasha’s calf," said Dr. Heather Schwartz, the zoo’s director of veterinary medicine. "Our staff has worked tirelessly to make sure this calf was given the best possible care. We moved from fear of a stillborn to joy of revival to anguish."
The zoo said Nasha is doing well and keepers will be giving her "an abundance of comfort and care" for the next few days.
According to the Giraffe Conservation Foundation, Masai giraffes face threats from poaching and are endangered due to population decline. Masai giraffes are noticeably darker than other species, with large, dark brown patches.