WATE: Authorities are investigating after a security guard was fired upon at the Watts Bar Nuclear Power Plant. It happened around 2 a.m. today on the TVA property near the Tennessee River about a quarter mile from the plant's protected area. Officials say the security officer was patrolling the area when he was shot at, he returned fire and was uninjured. The shooting lead the Watts Bar plant staff to declare an unusual event, which is the lowest of the Nuclear Regulatory Commission's four emergency classifications. The FBI will also be sending a team. A suspect has not been found.