Crews were called to a duplex on Princess St around 5:30pm.
The upper apartment was alight and crews had to force their way in and douse the blaze. No word on what sparked the flames.
Meantime, the Office of the Fire Marshal and Emergency Management is investigating a car fire in Wallaceburg.
Crews from Wallaceburg, backed by fire fighters in Chatham, were called the scene on King St. with reports of the vehicle ablaze around 9pm last night.
Nobody was injured.