SEATTLE - Woodland Park Zoo says the 45-year-old African elephant Watoto was euthanized Friday morning due to an illness.
The Zoo said keepers arrived early Friday morning and found the elephant lying down in the elephant yard and unable to move to an upright position.
"An elephant who is down and cannot get up has a finite amount of time," Dr. Darin Collins said at an afternoon press conference.
Animal health staff provided emergency care, but it was apparent Watoto's health was quickly declining and she would likely become more uncomfortable as hours passed.
"We helped her at the end by making a decision to euthanize," said Collins.
"The hard part is we have keepers who work here every day. And when you work with an animal for 30 years it's hard to lose them," said Bruce Bohmke, COO of Woodland Park Zoo.
The zoo said Watoto likely died of old age, but animal advocates say cramped quarters and the climate took their toll on Watoto.
"All the conditions here at Woodland Park Zoo are wrong and unhealthy for an elephant," said Alyne Fortgang of Friends of Woodland Park Zoo Elephants.
Related: Do elephants belong in the zoo?
Last month, the group packed a Seattle City Council meeting to urge council members to persuade the zoo to retire Watoto to a sanctuary in a warm climate.
They said the elephant was suffering from physical and psychological problems.
"I'm sad, but my first reaction is Watoto is finally free of the suffering that she experienced in the zoo," said Fortgang.
Watoto, who was the only African elephant at Woodland Park Zoo, was born in Kenya between 1969 and 1970, and joined the Zoo's elephant herd in 1971 as an orphan from the wild. She was considered to be the matriarch of the zoo's herd.
The Zoo had plans to send Watoto to another zoo by the end of the year.