Mike O'Reilly and Charity Dempster were in high spirits after spending the morning volunteering for the MS Bike Tour in Kamloops on Sunday.

But the day took a horrible turn at around 1:30 p.m. when they arrived to their duplex on Fernie Road in the West End to spewing smoke and fire trucks.

"I thought 'Oh my God that can't be my house!' " said Dempster, who immediately rushed toward the front door to retrieve her dog, a boxer named Belle.

A firefighter pulled her back, but seconds later the dog appeared in her neighbour's yard, seemingly happy and unharmed.

Both the duplex's front and back living spaces were unoccupied when the fire broke out.

O'Reilly, who owns half the house, said he was less concerned about the structure than everyone's well-being.

"As long as everybody's OK," he said. "A house is a house. I just wanted to make sure everyone was fine."

O'Reilly soon learned that his half was entirely unscathed due to a gap and firewall division between living spaces.

It wasn't such a happy outcome for the attached neighbours, however. The family renting the back half of the duplex moved in only five days earlier.

When two of the tenants arrived while firefighters were still at work, they got the tragic news that their home was gutted. And although their dog was saved, two cats and a rabbit were dead.

Fire investigators will be on scene this week to determine the cause of the fire, said assistant fire chief Curtis Bossert.

One clue may be found in neighbours' reports that they heard an explosion just before smoke began billowing from the house.

But Dempster suggested the sound could have been the large bay window at the back of the house shattering from the heat.