The four-seat car that contained six high school-age girls rolled through a stop sign at an intersection in Oklahoma before it was hit by a semi-truck, said federal investigators on Thursday. “Witnesses reported the (vehicle) made a ‘rolling stop’ at the stop sign and entered (the intersection)” before the collision with the semi that was carrying gravel that left all six teenage girls dead, said National Transportation Safety Board (NTSB) spokesperson Peter Knudson in a statement. The statement added: “The combination vehicle then departed the roadway and came to rest in a private driveway on the east side of (route) US 377. As a result of the crash, all six occupants in the Chevy were killed; the truck driver was uninjured.” Previously, officials said the girls range in age from 15 to 17. Their identities were not officially released by local or federal authorities, but family members mourned the girls’ deaths …