The fire broke out at a vacant home on 20th Street, just off Springfield Avenue, in Irvington just before 6 a.m., prompted residents of a neighboring building to flee.
Firefighters battled the blaze for about an hour before putting it out.
It caused damage to the second and third floors.
The neighboring building houses six families, but no injuries were reported.
The cause of the fire is under investigation.
Authorities are investigating reports that it was occupied by squatters.