A Madison middle school was evacuated Friday afternoon after staff smelled a natural gas and firefighters traced the odor to rotting cookies. According to the Madison Fire Department's Public Information Officer, Cynthia Schuster, fire crews investigated the odor at 2:38 p.m. Friday at Blackhawk Middle School on Wyoming Way. Schuster said an Madison Gas and Electric met firefighters at the school and identified the area where the smell was originating. The technician said the odor did not have the trademark smell of natural gas. Schuster said a school staff member led firefighters to a classroom where the scent was originally reported. Once inside, firefighters eventually traced the odor to a Tupperware container filled with cookies and protein bars.