GALESVILLE, Wis. -- The remaining charges have been dropped against a G-E-T teacher accused of burning students with dry ice.

Brady Olson, a high school chemistry teacher, was initially charged with felony child abuse and misdemeanor disorderly conduct for allegedly putting dry ice on the girls' legs in late January, leaving burn marks.

A Trempealeau County judge threw out the child abuse charge in April and the disorderly conduct charge was dropped Tuesday

The G-E-T Police Department and Trempealeau County Sheriff's Department conducted investigations, but found no criminal activity had taken place.

Olson, who has taught in the G-E-T School District for 16 years, had been put on administrative leave during the investigation.

G-E-T District Adminstrator David Grace says Olson returned to work April 12, after the felony charge was dismissed.