A malfunctioning heat trace has been determined as the cause of an Ibex Valley house fire which killed 69-year-old Donna Tull in April.

Yukon chief coroner Kirsten Macdonald and deputy fire marshal Kevin Taylor have concluded and made public their reports on the fire, which destroyed the home.

"The fire was caused by a malfunction of the heat trace,” reads Taylor's report, which was released this morning.

"Heat generated by the heat trace built up within the area of location of the well head, sun deck and penetration on the bottom of the structures west wall.

"The fire's origin was within this area and extended from this area to the interior of the structure.”

Tull lived alone in the 1,368-square-foot A frame house.

She had met with her son, daughter-in-law and a realtor the day of the fire to discuss selling the house and moving closer to Whitehorse.

Her home care worker had also been to the house the same day.

Just before the home care worker left at 2 p.m., Tull told her she was tired and was going to have a nap.

The investigation also found that Tull had a Lifeline System, which is described on Lifeline's website as "a personal response service that lets you summon help any time of the day or night.”

It was at 2:46 p.m. that Tull's Lifeline auto alert went out, with Tull indicating a minute later she needed the fire department.

A Lifeline operator made the initial call to the Whitehorse Fire Department.

That person was advised to call the Ibex Valley department because it was closer to Tull's house, notes Macdonald's report.

Finally, at 2:53 p.m., Ibex Valley firefighters were dispatched to Tull's home, seven minutes from when the first call went out to Lifeline.

Then, at 3:15 p.m., Tull made a call to 911 stating that fire was now coming into her home.

"During the call, the sounds of fire detectors in the background could be heard,” reads the coroner's report.

"The emergency operator is heard telling Mrs. Tull to exit the home and then the line goes dead.”

Ibex Valley firefighters were joined by their counterparts in Hootalinqua, Whitehorse and Golden Horn in responding to the call using the territory's Mutual Aid Agreement.

It was at 7:15 p.m. that the coroner's service was informed a body had been located inside the burned building.

Tull's body wasn't recovered until the following day, when it was safer to work on the site.

In looking at the significant factors, Macdonald concluded: "It appears that there was a delay in the most appropriate fire responders being dispatched to the scene.

"Lifeline operators called Whitehorse Fire Department instead of Ibex Valley Fire Department, which was the closest fire response system to the scene.

"This sequence of communication added to over five minutes to the response time.”

The "most significant factor” in Tull's death was not being able to get herself out of the burning building due to mobility issues and compromised lung function.

As Macdonald stated earlier in the report: "Mrs. Tull had a health history which required home oxygen. She also experienced chronic severe swelling in her feet.

"The swelling in her feet resulted in her inability to climb stairs and an overall reduced mobility.

"Mrs. Tull used a walker to navigate her home and relied on friends, family and Yukon Home Care to assist in her daily living.

"Mrs. Tull slept on the main floor of the home, because she could no longer climb the stairs to the loft bedroom.”

The coroner also noted later in her conclusion that "Everyone, but especially seniors, should consider creating and practicing fire escape plans.

"Fire escape plans should recognize and consider any and all mobility issues that may affect a person's ability to evacuate in the event of an emergency. In the event of a fire, escape plans may be critical to making it out alive.”

Macdonald then concluded Tull died of unnatural causes from smoke inhalation and carbon monoxide toxicity due to the house fire caused by the malfunctioning heat trace.

Her only recommendation was directed at Lifeline Systems.

That was to review her report "and ensure that applications for Lifeline Services for rural Yukon clients clearly identify the closest, most appropriate emergency services for dispatch to ensure the most timely response.”

Lifeline could not be reached for comment by press time this afternoon.