A doe that attacked and seriously injured an 85-year-old woman in Craig was captured and killed by state wildlife officials because of her “extremely aggressive behavior,” according to a news release.

The deer attack, which is highly unusual, happened at about 4:30 p.m. as the woman was walking her dog within city limits, according to Colorado Parks and Wildlife. The woman was taken to Craig Hospital with serious injuries.

Wildlife investigators believe the doe attacked when the woman and her dog surprised the animal, the release said.

“Doe attacks are rare but wildlife officers say they can happen and they can be serious, especially when the animal is rearing her young,” the wildlife division said.

Wildlife officers found and captured the doe and her fawns at about 8 p.m., the release said. “In accordance with agency policy and due to the doe’s extremely aggressive behavior, CPW will put the animal down to protect public safety.”

The doe’s carcass will undergo a necropsy at the Wildlife Health Lab. The fawns were taken to a local rehabilitation facility.

Craig, a town of 10,000 in northwestern Colorado, has a large mule deer population, the release said. Wildlife officers warn residents, and the public, not to approach wildlife, especially females with offspring.