Arson investigators are on the scene to determine what caused a fire near Republic Airport.Officials say a fire started at the old Fairchild Building next to Republic Airport just before 5 a.m. Monday. More than 100 firefighters from five different fire departments arrived to battle the blaze. The fire caused Conklin Street between New Highway and Route 110 to temporarily be shut down.Officials say the building has been abandoned for at least 25 years and was used as a hangar by Republic Airport. They say recently they have had problems with squatters in the building.There were no reported injuries due to the fire. Officials say they aren't sure if anyone was inside when the fire broke out.