'Wonder dog' saves couple from fire

Tank, the puppy, has been hailed a life-saver after alerting his sleeping owners to a devastating fire engulfing their Hobart home.

Jasmine Gillie, 22, and her boyfriend Josh Saunders, 20, were asleep inside their rented weatherboard home in Mornington early this morning when the large four-month-old terrier cross Tank began jumping on their bed and barking.

The couple said a fire which had started in a clothes dryer had spread quickly through the house and filled their room with smoke.

They ran naked, but uninjured, from the house just minutes before it was engulfed in flames, they said.

"If Tank hadn't have been there we would not have woken up -- he saved our lives," Mr Saunders said.

Ms Gillie said Tank would get a big bone as a reward.

Firefighter Gavin Freeman said Tank was a hero.

"I'm not sure yet why the home's smoke alarm didn't go off but Tank the wonder dog got to them first," he said.

"The dog really saved them - there's no two ways about that."

Emergency services were called to a separate, fatal house fire in Hobart only a few hours later.

Police said a 29-year-old man died trying to escape the blaze in Bridgewater at 4.30am AEDT (6.30am NZT).

"From early indications it appears the fire started from a cigarette which had not been properly extinguished, causing a lounge to smoulder for some time," a police spokesman said.

"The fire had been contained to the lounge room area of the house however the man has been overcome by the volume of smoke and has been unable to escape the fire."

A smoke alarm was fitted to the Bridgewater house, firefighters said.

- AAP