PHOENIX — Unsafe work practices and the failure of supervisors to follow policies and oversee workers led to a wildlife biologist’s plague death at Grand Canyon National Park last year, according to a federal report released on Tuesday.

The report by a National Park Service review board said Eric York, 37, didn’t wear gloves or a protective respirator while handling and performing a necropsy on a mountain lion that had died of the plague.

York’s supervisors didn’t monitor his activities or review job hazards, he was never trained on the potential of catching diseases and the Park Service didn’t formally assess the danger he and other workers could encounter on the job, the report said.

York worked in the park’s cougar collaring program and fell ill days after he used a locator beacon to track a mountain lion that had stopped moving.

He recovered the body, took it to his home at the South Rim of the Grand Canyon and did a necropsy in his garage. Several days later, be began feeling ill and went to a clinic.

A physician there suspected flu and wasn’t told of York’s regular exposure to wild animals. The plague is endemic to northern Arizona, but he wasn’t tested for the disease. The report noted that workers and medical personnel should be trained to ask about possible exposures when seeking or giving medical help.

York was found dead in his home six days after retrieving the dead animal on Oct. 26, 2007.

Deputy park superintendent Palma Wilson acknowledged Tuesday that the agency made mistakes.

“There were protocols in place, but we were not necessarily ensuring that those protocols and safety standards were being followed,” Wilson said.

Although the report was just made public, it was completed in May. It recommends a series of changes to ensure worker safety.

Wilson said its release was delayed while it was reviewed at higher levels at the Interior Department and its conclusions shared with York’s family, who live in Massachusetts.

“As soon as we got the initial report back from the Board of Review we started implementing those recommendations,” she said. “This was a tragic death, but if some good could come from it it would be that we can get the word out, we can get the safety protocols out so that no one else has to go through this.”

York had worked in the Grand Canyon for two years. He had worked previously for state parks in California and had traveled to Nepal, Chile and Pakistan to work with protected animals.