Heater likely cause of townhouse fire

Fire crew assess the damaged property at Cutten St in South Dunedin. Photo by Craig Baxter

A heater used to "warm up the bed clothes'' is the likely cause of a fire which gutted a South Dunedin townhouse, forcing occupants to flee early this morning.

Three appliances from the St Kilda, City and Lookout Point fire stations attended the blaze in Cutten St about 12.40am.

"The occupants have told us they were... heating up the bedding or the bed,'' Dunedin City Senior Station Officer Rob Torrance told the Otago Daily Times this morning.

A dividing wall separated the two flats, with the fire reportedly starting at the front of the house where two occupants slept.

Earlier, southern fire communications shift manager Andrew Norris said both flats had been "extensively damaged" and would likely be demolished later today.

Mr Norris said when fire crews arrived they found the house was two flats.

"The fire had spread from the front flat to the back flat, and they were both well involved in fire when we got there."

Luckily, the tenants from the front flat were awake, and they managed to escape from their home and alert the tenants at the back flat.

All four tenants from the two flats managed to escape the blaze uninjured, Mr Norris said.

"The firefighters have indicated that there were no working smoke alarms, and had the people been asleep at the time, they are sure the outcome would have been far different to what it was."

The fire was not being treated as suspicious.