MONTREAL -- Three people have now died following a fire last month in a Lachine apartment complex.

A 5-year-old girl who survived the initial blaze had been fighting for her life in hospital for almost a month, Montreal police spokesperson Jean-Pierre Brabant said.

She died on Friday.

The girl's mother, 40, and sister, 8, died in the fire.

Two young brothers, aged 13, were in the home at the time of the fire, but they jumped from a second-storey balcony to escape the flames and sustained minor injuries, Montreal police said.

Neighbour Alain Makelele told The Canadian Press in November that he and another man caught the boys after they jumped.

"They were crying that their mother was still in there with their little sister, and as soon as we were in sight of it, the apartment was in flames," he said.

An unattended cigarette may have sparked the inferno, but officers have not finished their investigation, Brabant said on Tuesday.

Police said at first that the girl was 4 years old but later found documentation showing she was 5.

Firefighters were unable to determine if the home's smoke detector was functioning but many other smoke detectors in the same building were not

With files from The Canadian Press