Fire units responded this morning to 3900 South Clinton Avenue for a reported fire in the building. Arriving units located a dust collector on fire on the Wade Avenue side of the complex on the roof. Engine 5 was directed to Wade Avenue and stretched up the exterior staircase to the roof to place their line in operation. Truck 7 was detailed to overhaul and search operations. One engine from Plainfield Fire was relocated into quarters for coverage. Chief Scalera in command.