A busy weekend for fire crews in Ottawa. A house fire yesterday morning has left a family of four displaced. The call can in about 7:45 yesterday morning and the Ottawa Fire Department responded to the structure fire at 529 North Oak. Arriving on the scene, crews found, fortunately, that all the occupants of the home had escaped the home safely and heavy smoke and fire was coming from a single story residence on the northeast corner of the street and immediately went to work extinguishing the fire. Crews remained on scene until just before 10:30. Fire Chief Tim Mathias says the structure sustained significant fire, heat and smoke damage. The cause of the fire was not released and Mathis stated that it is still under investigation and did not release any damage assessment.