The last three victims died on Sunday and Monday but authorities only released the information Wednesday.
The fire started Sunday morning on the first floor of a two-story apartment. The smoke detector on that floor was missing a battery, however.
While another smoke detector on the second floor was functioning, poisonous vapors could have traveled upstairs in minutes, said Assistant Fire Chief Bob Khan.
''It was a survivable fire,'' Khan said. ''If they had a working smoke detector (downstairs), they could have gotten out.''
Neighbors put a hose through a window to try to put out the fire and tried to kick down the front door but were unsuccessful. Firefighters eventually broke into the house. None of the victims were breathing when they were found.
The first victim, Corey Stewart, died Sunday.
The other victims were identified as Stewart's girlfriend, 30-year-old Abbey Milligan, and two of her children, 7-year-old Timothy Lawn and 5-year-old Eric Lawn, Kahn said.
Eric also died Sunday, police said. The other two died Monday.
Another of Milligan's sons, David Milligan, 13, survived but remained in extremely critical condition Wednesday, according to police.
The cause of the fire was under investigation. Kahn said it could have been started by a broken candle or a cigarette. Officials were also looking into whether one of the younger boys could have started the fire.
