Both occupants of a Nissan Altima that overturned and collided with the end of a guardrail on McMinnville Highway Monday night were airlifted due to their injuries.According to the Tennessee Highway Patrol, 21-year-old Michael Briley of Blue Springs Road and his 16-year-old female passenger were transported by Life Flight and Life Force helicopter after the crash on Highway 56 just south of Seven Springs Road.The incident occurred just after 9 p.m. Briley was apparently driving north on in the 2003 Nissan when he crossed the center line, went off the left side of the highway, struck an embankment and overturned, hitting the end of a guardrail.Both victims were treated by DeKalb EMS and then taken to the helicopter ambulances, which were landed in a field near the accident scene.Trooper Jeremy Wilhite and Trooper Craig Wilkerson investigated the crash, and were assisted at the scene by members of the DeKalb County Volunteer Fire Department and the sheriff's department.