All Operations Are Back To Normal At Tri Cities Regional Airport. Officials Officials Have Confirmed Nothing Hazardous Was Found At The Facility. This Following An Alert From A K-9 During A Routine Security Sweep. An Explosive Ordinance Team And K-9 Units Isolated A Mailbox In The Terminal Building At The Airport. The Mailbox Contents Were Evaluated. No Threats Were Received Either. Several Flight Delays Were Experienced Because Of The Situation.