A Bucklin teen is dead and two Marceline residents injured following an accident Wednesday night in Chariton County.  The Missouri State Highway Patrol reports Ashley Simpson, 24, crossed the center line of Route JJ and struck an oncoming vehicle being driven by Zachary Cupp, 17.  Investigators said they collided nearly head-on.  Cupp was pronounced dead at University Hospital at 3:30 a.m. Thursday.  Simpson and her passenger, Katrice Sartain, 27, were transported to Pershing Memorial Hospital with minor to moderate injuries.  The accident was reported just prior to 11:00 p.m., about two miles west of Marceline.