Fire department spokesman Frank Dwyer says the fire was ruled accidental. The utility Consolidated Edison says the three-story Bronx building had no power because there was no record of anyone living there.
Christian Garcia and his parents, Juan Lopez and Christina Garcia, died in the April 25 blaze. Christian's younger brother and sister escaped the top-floor apartment. Lopez's brother, Lucio Arturo Gonzalez, says the family wasn't using candles and he believes the fire started on the floor below.
City officials say access to fire escapes was blocked.
The building was in foreclosure. Its ownership was disputed.
The case led to a city crackdown on illegal subdivisions.