Just before 1800 hours, township companies were dispatched to 110 Chesley Dr for the fire alarm. Ladder and Chief 65 along with 51-9B arrived with nothing evident. As crews from Ladder 65 forced entry to the building, a light haze and odor of smoke were evident on divisions 1 and 2. The assignment was then upgraded to the building response bringing additional resources. Ladder 65 placed a line in service and laddered the building. Crews located a fire in the basement that had been knocked by the sprinkler system. Engine 51 laid in from the hydrant to the connections and Ladder 65. Crews had no extension and the fire was placed under control.