The cause of a devastating house fire that killed a Cheyenne woman two weeks ago may never be known.

Cheyenne Fire Marshal Byron Mathews says the cause of the February 25 blaze that took the life of 68-year-old Sharon Stoner at her 3515 Amherst Road home is "undetermined."

"We were able to conclude the fire started on the ground level of the two-story addition which was attached to the back of the house," said Mathews. "However, we were unable to determine what exact point and what exact event came together to cause that fire."

"We look for the first materials that would have been ignited, what caused that ignition," Mathews added. "This fire just happened to have a head start. It got a lot of oxygen and a lot of that evidence that we were looking for was destroyed."

Mathews says the house, which sustained $288,554 in damage, did have working smoke alarms at the time of the fire.