(CNN) -- An elk's close encounter with a photographer prompted Great Smoky Mountains Park officials to euthanize the animal.
The video of the young bull elk nudging and head-butting James York, who was sitting on a North Carolina roadside, spread quickly through Facebook, Twitter and YouTube last week.
While most people saw a fascinating exchange between human and beast, wildlife biologists saw danger.
"By initiating physical contact with a visitor, the elk displayed an unacceptable risk to human safety," a park statement released Monday said.
Humans visiting the Cataloochee area of the national park had apparently been feeding the young bull elk, which then "lost his instinctive fear of humans," officials said.
"After becoming food conditioned, the elk did not respond to any attempts to keep it out of the area and away from humans," they said. "When wildlife exhibits this behavior it often escalates to more aggressive behavior creating a dangerous situation for visitors." The animal had a history of "approaching visitors seeking handouts," they said.
Wildlife biologists "made the difficult decision to euthanize an elk" last Friday.
Park officials knew of this elk's familiarity with humans before the video racked up millions of views online.
"Between September and last week, park biologists aggressively hazed this elk 28 times to discourage it from approaching the road and visitors," they said. "They captured, sedated, tagged, and re-released it on site."
"The behavior that it learned from park visitors who had given it food had been too strongly ingrained," making it unlikely the elk would change his offensive ways, they said.
York, who hunched over and and remained still through much of the encounter, was not injured, but "if the animal had approached a child instead of an adult, the outcome for the visitor could have been very different," park officials said.
This elk was the first euthanized in the park since the animals were reintroduced there by park officials 13 years ago, the release said.
Elk once were populous in the area but were gone from the region by the mid-1800s due to over-hunting and loss of habitat, according to the national park's website.
CNN's John Branch contributed to this report.