A Porter Creek family's home suffered extensive damage Saturday after an early-morning blaze that started by a smouldering cigarette butt.

A neighbour called 911 after smelling smoke on his way out of his own home across the street at about 1:30 a.m. Saturday.

After he noted the stench and spotted flames, the neighbour ran across Cedar Crescent and woke up the sleeping family, Whitehorse RCMP spokesman Sgt. John Sutherland said this morning.

The mother and her two children got themselves out of the burning house safely and were not injured.

Earlier, a cigarette had been butted out in a planter on the back deck. The cigarette had smouldered in the peat moss before igniting into flames, said fire chief Clive Sparks.

'It would smoulder quite a long time in there,' he said this morning.

The Whitehorse Fire Department was called at 1:39 a.m., and was on scene for more than three hours, Sparks said.

When the first fire truck arrived, flames were licking up one corner of the house into the roof and attic.

The blaze was contained to those areas, and there was very little smoke damage to the interior. However, there was extensive water damage to the one-storey home, said the fire chief.

He estimates the structural damage at $100,000 and damage to the home's contents at $15,000.

The roof and attic must be replaced, along with many of the interior walls, ceilings and floors damaged by water.

One pumper truck, the rescue truck and 12 firefighters were used to contain the blaze.

It was the first fire of any significance all year, Sparks said.