The parents of three children who died in a house fire last month may never know how the fire started.
Sioux Falls Fire Rescue investigators say they were able to determine the December 22, 2012, fire started in the living area but the damage was so severe, they cannot determine how it started.
The insurance company provided an electrical engineer to help investigators determine whether the fire was electrical in nature but they were able to rule it out as a cause.
An accelerant-sniffing dog walked through the home twice, once immediately after the fire, and again after officials reinforced the structure and after the house thawed out, and was unable to pick up any scents.
The fire killed siblings six-year-old Alivia Coon, 12-year-old Savannah Coon and 16-year-old Michael Hensley.
Their mother, Rhiannon White, was later arrested on drug charges after officials say tests from her emergency room visit revealed she had meth, ecstasy and marijuana in her system at the time. Officials say they did not find any drug paraphernalia in the home during their investigation.