A man has been transported to hospital with serious burns following a house fire in the Mount Pleasant and Blythwood Roads area that left a woman dead.

The pair were husband and wife, and believed to be in their 80s. Reports suggest she was bedridden and a heavy smoker.

The man was trying to carry his wife out of the burning house when he succumbed to his injuries, sources told CTV News. He is at Sunnybrook Hospital for treatment of burns to his hands, legs and feet.

Police at 53 Division said they are required to investigate all unnatural deaths as suspicious, but are "pretty confident" it wasn't arson.

"We have a pretty good idea what happened," Det. Murray Barnes told CTV News. "We're in the process of going through all avenues to make sure we don't miss anything."

Ontario Fire Marshal investigator Mike Ross said it is too early in the investigation to determine whether smoking sparked the fire.

Seven fire trucks were at the scene Tuesday afternoon, which is roughly half-way between Lawrence and Eglinton Avenues East.

The call came in just after 4 p.m. Aerial images shot about 4:30 p.m. didn't show any flame or smoke. Firefighters continued to work on the roof of the multi-level home.

So far, 10 people haved died from fires in Toronto. There were 18 deaths in all of 2009.