The Kalispell Fire Department says a 57-year-old man who died in a house explosion last week intentionally set the blast to kill himself.

Fire officials say propane cylinders, chemicals, live ammunition and other accelerants were strategically placed throughout the residence and property to hamper efforts by emergency responders.

Notes were placed on the front and rear of the property advising public safety personnel to stay away, but officials didn't see the notes until the fire was out.

The investigation found no evidence that natural gas was a factor in the March 9 explosion.