The death of a man, who was found unconscious in a rooming house fire last week, is now being considered a homicide by Calgary police.

Daniel McWha, 57, was transported to hospital on Sept. 12, but later died from his injuries. Three other people were rescued by fire crews that night from the roof of the rooming house.

Police said Tuesday the death is being treated as a homicide based on the autopsy results and an investigation of the scene.

"Someone was inside the house when the fire was set. We're trying to determine the comings and goings of that location, and who has access to it, and who is there on a regular basis or who may be previous tenants or known of it," said Staff Sgt. Grant Miller.

Police don't have any suspects, he said.

"We're not ruling out the fact that someone in the house may have been targeted, or that this victim was specifically targeted. It's too early to tell yet."

Investigators said the CPS Homicide Unit, Arson Unit and the Calgary Fire Department have determined the fire was deliberately set.