"The Conservators Centre is devastated by the loss of a human life today," the statement said.
The centre said the lion was shot and killed to allow county personnel to retrieve the injured worker.
"This is an ongoing investigation, we have no further details at this time, and the family has not yet been notified. We will offer more information as we know more," the statement said.
The facility was founded in 1999 and is in Burlington, northwest of Raleigh.
On its website, the centre said it began giving public tours in 2007 and gets more than 16,000 visitors annually. It has more than a dozen employees and currently houses more than 80 animals and more than 21 species.
The centre says it took in 14 lions and tigers in 2004 to assist the US Department of Agriculture with caring for animals that were living in "unacceptable conditions".
A message seeking comment was left with a spokesman for the county sheriff's office.
- AP