A family of four and a boarder who lived in their home died in Whitehorse in January 2012 from carbon monoxide poisoning. (CBC)

An inquest into the death of a Whitehorse family has heard they knew something was wrong before they died, but they didn't know what.

Last January, Bradley Rusk, 45, his wife Valerie, 37, along with their children Gabriel, 13, and Rebekah, 11, died in their Porter Creek home. Donald McNamee, a 47-year-old boarder who lived in the home, also died.

Firefighters investigating the scene concluded a faulty chimney was to blame. A preliminary report for the Yukon coroner concluded all five people died from carbon monoxide poisoning.

A six-member jury was sworn in Monday morning to consider the evidence at a coroner’s inquest into the deaths.

The inquiry heard that just days before they died, Valerie had gone to her doctor’s office in tears, begging for an appointment to find out why she and her family were so sick.

They all had headaches and were feeling weak and nauseous. An appointment was made to see the entire family the next day, but the Rusk family was too sick to make that appointment. They died a few days later.

Firefighters testified Monday that the moment they entered the Rusk family home, their toxic gas detectors went off the scale with lights flashing and bells ringing. But other than that, the home was quiet. The veteran firefighters with decades of experience each said they had never seen anything like it.

There was no sound from any carbon monoxide detectors in the home, and even though firefighters found the curtains and bedding coated in soot, there was no sound from any smoke alarms. Photographs from inside the home show the smoke detector was covered in soot, and the houseplants were dead or dying.

The jury’s task is to find out if there are any lessons that can be learned from the death.

The inquest is scheduled to last all week.