We finally know what started the deadly cabin fire in Donnelly this summer that killed four people, two of them children. 

Officials say an uncapped propane line that pooled behind a fireplace caused the explosion in Donnelly on June 30th that claimed the lives of 49 year old Lt. Col. James Harper III, his 14 year old son James "JJ" Harper, 35 year old MSgt Erin Smith and her 6 year old daughter Autumn.

They say what happened is that the cabin fireplace had been converted from a gas fireplace to a wood fire place and that no one was aware that gas had been leaking behind the fireplace for several minutes before the explosive blaze happened. Erin's husband, William Smith, who was on the other side of the room farthest away from the blaze tried to save everyone, but it was hopeless.

According to KTVB, the original propane line was left in place to fuel the other three fireplaces in the cabin that were still gas.

So far we still don't know if the rental company or the person who built the fireplace will be found liable or not.

It's such an unthinkable tragedy, that our thoughts continue to be with Erin's husband and anyone else affected by this horrible loss in our community.