A dangerous rooming house fire that sent three men to hospital could have been far worse, Toronto firefighters say after discovering nine broken or missing smoke detectors inside the home.

Toronto Parkdale rooming house fire

Toronto firefighters rescued three people from this Parkdale rooming house on Tuesday. (CBC)

Toronto Fire Platoon Chief Chris Bertram said the fire started in the kitchen of the semi-detached home on Wilson Park Road in Parkdale around 11:30 a.m. Some residents fled, pulling a fire alarm on their way out, but others remained inside.

Firefighters entered the house to find heavy smoke on the first floor and pulled three people from the home, including one person who was taken to hospital in critical condition.

Bertram said that person has since been stabilized in hospital.

Firefighters discovered at least nine smoke detectors that were considered not operational or missing after extinguishing the blaze, Bertram said. Ontario Fire Marshal investigators remain on scene.

"There was one in the basement that was emitting an audible tone but very weak as the battery was near dead in it. The others ones were not operational," he told reporters.

"This is something we sadly encounter too, too often and public education has to continue and landlords have to inspect their properties and keep them up to working condition at all times," Bertram said. 

Victim looked 'awful', witness says

Neighbour Frank Trotz, who called 911 after seeing smoke coming from the home, said he watched as firefighters staged the rescue. The last victim, he said, was naked and appeared to be unconscious.

"He looked awful," Trotz said, adding he was glad to hear the man is OK.

Trotz said he isn't sure how many people lived in the home but said he'd seen multiple people moving in over the last four months.

One resident of the home, who declined to provide his name, said the home is a rooming house.

Rooming houses are allowed in Parkdale and across the former city of Toronto and are also allowed in York and Etobicoke. However, rooming houses are banned in North York or East York, and Scarborough.

There have been several major rooming house fires in recent months, including a fatal incident in Scarborough and a major blaze in Kensington Market