NASHVILLE, Tenn. (AP) — The security contractor at the Y-12 nuclear weapons plant in Tennessee was fired Monday after authorities said three protesters cut through fences and vandalized a building in an unprecedented break-in.

Security contractor WSI Oak Ridge said it has started winding down operations and will transfer its protective force functions to B&W Y-12, the managing contractor at the plant, over the next several weeks. The Department of Energy had earlier recommended that WSI’s contract be terminated.