The Dane County Sheriff’s Office is investigating a two-vehicle crash in Cross Plains that left a driver dead.  A concerned citizen called to report a car driving all over County Road around 3 P-M Friday.  Deputies say the northbound car crossed the centerline a minute-and-a-half later and was struck by a southbound vehicle.  The man driving erratically was transported to the U-W Hospital where he later died.  A woman in his car is hospitalized with life-threatening injuries.  Two people in the other vehicle were treated for less serious injuries.