CASCADE, Wis. (WHBL) - Two Cascade teens were injured Tuesday morning when their car hit black ice on County V just north of the village of Cascade shortly after 7 o'clock. The Sheriff’s Department said 17 year old Savannah Johnson was driving the van that left the road, went down into the ditch, hit two mailboxes and then hit a culvert and flipped onto its top. Savannah’s teenage sister and brother were riding with her. Sgt. Blaine Spicer said she was able to get out of the vehicle and run to a nearby residence for help. Savannah was later taken by ambulance to Aurora in Grafton and then flown to Froedert in Milwaukee for treatment of neck and head injuries. Her 14 year old sister suffered a minor injury. Her 15 year old brother wasn’t injured. All were belted in.