The latest deadly Paris blaze engulfed a dilapidated building used to house African immigrants in the central Marais district.
The fire, the second serious blaze within a week, is said to have started on the lower floors and spread rapidly, trapping many people.
Four children were among the seven killed and many others were injured. African immigrant groups have urged the authorities to provide better housing.
About a dozen families from the Ivory Coast lived in the dilapidated building. Those who fled the blaze were overwhelmed by their experience.
An estimated 100 firefighters and 30 fire engines were called out to tackle the fire - the third such blaze to hit African immigrants this year.
As the flames died down survivors were asking how and why it had happened again.