SAUGUS — A truck rollover resulted in one death Wednesday afternoon on Route 1 South, near Saugus plaza by the Walnut Street overpass.The roadway, including Route 1 South and the cloverleaf exchange that connects Walnut Street with Route 1, was shut down for emergency equipment and to reduce traffic on the southbound side. Saugus and State Police cruisers were both on scene.First deemed serious on social media sites, such as Twitter, it was confirmed as a fatality within the hour.The victim?s name has not been released, pending notification of next of kin.In the early stages of the accident, traffic was diverted to Walnut Street. Motorists were warned to expect delays.Liet. Ronald Giorgetti, of Saugus Police Department, said Massachusetts State Police is the investigating agency.Drivers are advised to seek an alternative route.Tara Vocino may be reached at [email protected].