Lakewood, Co – Fire investigators say all evidence points to natural gas as the reason behind an explosion that injured a Lakewood woman Friday.

West Metro Fire says they got a report of a house explosion at 17th and Ingalls around 4:15 p.m.

The explosion knocked the house off its foundation. It was a total loss.

“I was painting my bedroom,” neighbor Ron Dembinksi told 9NEWS. “All of a sudden I saw the lights blink. I thought, ‘That’s odd. I’m going outside and look around – something’s wrong.’ And the next thing I saw was this huge ball of orange flames go 30, 40 feet in the air.”

Investigators say they have not identified an exact leak, but say it appears the furnace ignited natural gas within the return air supply system for the home.

They also say they have not found any evidence that the fire was intentionally set.

The 52-year old victim says she smelled natural gas for the past two days and on Friday, she was ironing in her back room when she heard two small explosions.

She tried to run out of the house when the third explosion caused the house to burst into flames.

The victim, whose name is not being released, is in the Burn Unit at University Hospital.

Authorities say she had second-degree burns on 20 percent of her body, mostly on her face and arms.