An early-morning blaze at a downtown apartment building was believed to have been started after a 42-year-old resident fell asleep on his couch with a lit cigarette in his hand, Toronto Fire said.

Residents of the building on Alexander Street, near Yonge and College, say the saw flames shooting out of a 14th floor unit.

"I couldn’t see through the peephole (because the smoke) was so thick," neighbour Robert Miskiewicz told CTV Toronto.

He said he heard the fire alarm going off shortly before 2 a.m.

About 45 firefighters battled the two-alarm fire that ripped through the suite. The unit's resident and his blind dog were loaded into an ambulance. He was treated for smoke inhalation.

Toronto Fire says the blaze caused about $120,000 worth of damage.

Sunday's fire wasn't the first time firefighters have responded to an incident possibly linked to careless smoking at the downtown building.

In the last decade, Toronto Fire have been to the same building for at least three other fires – and all of them were believed to have been started by cigarettes.

In January 2004, a fire on the fifth floor of the building broke out. No one was injured in that incident, but the next day, firefighters were again called to the building. This time, a man was killed and another was injured.

"The person who was injured said the other gentleman whose clothing was on fire was coming down the hall from the bedroom area," a spokesperson for Toronto Fire told reporters at the time.

In 2014, firefighters were again called to the apartment when a fire broke out in the same unit as Sunday’s incident.

"I guess people should be a little bit more responsible," Michael Doyle, another resident of the building, told CTV Toronto.

With a report from CTV Toronto's Tamara Cherry