The bell at the Spencer Brook Premiere School has been missing since Friday.
Executive Director Kathy McCully of the Isanti County Historical Society said she can't believe the bell is gone from the 150-year-old school.
Since the building is so high, it's believed the thieves may have used a lift to get on the roof. Once the thieves were up there they damaged the cupola and put a hole in the roof before making off with the bell.
The cast-iron bell weighs more than 200 pounds, and is about 18 inches in diameter and the same in height.
The historical society believes it's possible the bell will be sold for scrap metal.
A $500 reward is being offered.

