Watertown Fire Rescue(WFR) responded to a house on fire in the 1000 block of 2nd Ave SE at approximately 8:30 Thursday night. Upon arrival the family was out of the home and smoke was seen coming from the windows. Crews made entry into the home and found thick dark smoke that reduced visibility, with the use of thermal imaging camera the crew was able to find and extinguished the fire. Fire damage was limited to the basement but unfortunately the rest of the home had significant smoke damage. Cause of the fire is still under investigation. WFR was on scene for 2 hours.