Hope the black bear, made famous after her birth was broadcast live on the internet, is believed to have been killed by a hunter.
Hope and her mother Lily, from near Ely, Minnesota, were studied by researchers and also starred in a BBC documentary called "The Bear Family and Me," according to BBC News.
Biologist Lynn Rogers and colleagues at the North American Bear Center and its affiliated Wildlife Research Institute were tracking 13 bears wearing collars.
Hope is thought to have visited a hunter's bait station three times. A hunter has contacted the research team to confirm that he killed a young female bear in the area on Sept. 16.
While recreational hunting is permitted by licenses in Minnesota, hunters are asked not to shoot bears wearing radio collars, the BBC says.
The hunter thought to have killed Hope the bear has not been publicly identified.
"I'm figuring I'll never release his name," Rogers said, adding that the center's goal is to "peacefully coexist with hunters. ... We just want to know what happened and go on from there."
Still, Rogers said he has to wonder if the hunter deliberately sought out Hope. He said the hunter has posted messages before on a Facebook page with around 50 fans called "Lily: a bear with a bounty," where some postings last week spoke of "Hope jerky" or Hope cooked in a crockpot.
According to the BBC, Hope the bear was born in 2010, and "as part of their behavioral research, the team placed a camera in Lily's den and filmed Hope's birth — a labor that lasted 22 hours and resulted in a single cub."
Thousands of people watched Hope's birth on the internet, while Lily the black bear's Facebook page has more than 132,000 fans.
Rogers and the other researchers posted a message to fans on the Facebook page:
As we come to grips with the loss of Hope, we are mainly thankful for her life. She brought people together to learn about black bears. She was part of the biggest worldwide bear education project we know. She has changed the attitudes of thousands, perhaps millions, through the internet and documentaries. Her death is a tragedy. There is so much more we all could have learned.
The BBC says that Rogers has spent the past 45 years studying black bears, and he has habituated them to his presence.