The final teen charged with arson for a fire that destroyed a historic covered bridge in Madison County last year has pleaded guilty. Eighteen-year-old Alex Hoff of West Des Moines pleaded guilty to second degree arson and criminal mischief Monday morning. His sentencing has been scheduled for April 23rd. Nineteen-year-old Alivia Bergman and 18-year-old Joel Davis were also charged in the case. Bergman pleaded guilty to second degree arson back in December of 2017. Davis pleaded guilty to second degree arson in February. Davis will be sentenced April 16th. Sentencing for Bergman is set for May 7th.