Whitehorse firefighters knocked down a potentially volatile balcony fire in Hillcrest Monday afternoon before it broke through into the roof and outside wall.

Fire chief Clive Sparks said today the balcony was ablaze when firefighters arrived. However, it was quickly doused, enabling the crew to run a ladder up to the second-storey apartment to make sure the blaze was out and inspect for further damage.

The cost of repairs to the Terra Apartments building on Roundel Road is likely about $7,500, Sparks said this morning.

There were no injuries.

The chief said the cause was a portable smoker that had been placed inside a wooden box and left unattended on the balcony.

Firefighters could determine by removing insulation from the exterior wall that they had doused the blaze before it could spread any further.

The call was received at 3:30.

Had the fire been given any more time to breathe, there is no telling how ferocious it may have become once it got into the roof and walls, he explained.

Smokers, said Sparks, should never be left unattended. Nor should not be placed inside a box or any type of container to increase the heat and smoking effect, as that only increases the risk of fire.