Investigators believe spontaneous combustion sparked a fire at a large grain storage bin owned by Western Grain Marketing.
The bin at Routes 136 and 41 reportedly had 700,000 bushels of dried corn in it when the fire started Monday afternoon.
Several fire and law enforcement departments were called to the scene. Initial efforts to extinguish the fire were unsuccessful so Macomb Fire Chief Andy Taylor said several different techniques were tried to bring it under control.
The fire was finally extinguished roughly 24 hours after it started.
The Illinois Department of Transportation rerouted traffic due to the heavy smoke and because of concerns that the fire might cause a grain dust explosion.
The intersection reopened to traffic mid-afternoon Tuesday.