But officials still don't know the exact source of the March 5 fire.
WISC-TV reports fire officials say the fire started in the dining room, and could have been started by different items, including a ceiling light fixture, wiring associated with the light fixture, light bulbs or a humidifier.
Authorities say there were two battery-operated smoke detectors in the home, one in the basement and another on the main level.
Sixty-one-year-old Clint Christensen and his 33-year-old daughter, Jaime Christensen, died in the fire. A third victim, 60-year-old Caren Christensen, was treated and released from University of Wisconsin Hospital in Madison.