Staff mourn little Leelee
Leelee, a two-year-old female Asian elephant, has been struck down by the same deadly virus which killed Donaldson, a one-year-old male calf.
She began showing signs of elephant endotheliotropic herpes virus (EEHV) on Friday, May 15, and immediately began undergoing treatment.
The little jumbo was also given a blood plasma transfusion, but sadly died on Sunday, May 17. Vets battled for 50 hours in vain to try to save her.
Zoological director David Field said: "Leelee battled this virus with all the bravery and dignity you come to expect from one of these magnificent animals.
"Losing an animal is always terrible, but we have worked so hard to establish a strong breeding group that this setback is a real blow to everyone.
"The keepers and vets worked tirelessly in their efforts to save her and could not have done more."
Since the virus was first identified in 1995, there have been more than 50 cases in American and European zoos and it has also affected wild elephants.
Mr Field said: "ZSL (the Zoological Society of London) already puts significant time and resources into researching this virus through collaborative work with other zoos and veterinary institutions worldwide.
"We are as determined as ever to find a cure or vaccine for this virus."