An early-morning fire at a 14-story apartment building in Tokyo's Arakawa Ward killed one person Sunday, and five people are being treated for smoke inhalation, firefighters said.

The fire occurred at around 6:45 a.m. and swept through a 45-sq.-meter room on the 14th floor of the No. 13 Tokyo Municipal Apartment, according to the Tokyo Fire Department.

The department believes the deceased is Kyoji Haga, a self-employed man who lived in the room.

The cause of the fire is under investigation.