Cedar City police described the item as a cylindrical package with tape on both ends.
Police said that part of the building was cleared so that students could leave for lunch while crews worked to make sure the scene was safe.
Lt. Darrin Adams of the Cedar City Police Department told ABC 4 that the St. George bomb squad was called in to investigate the package.
Adams said the bomb squad used a robot to destroy the package - which turned out to be a cardboard tube filled with dry beans.
Adams said the tube was most likely a makeshift noisemaker or musical instrument that was dropped by mistake.