Bimala Devi (60) and Kamal Nath Rana (38) residing at an adjoining tile-roof house sustained minor injuries in the wall collapse that took place on Canal East Road, a senior officer of the Kolkata Police said.
A part of the house was also damaged.
Murgaluddin and Gopi, two promoters of the building, were arrested.
"The fourth floor on the said building is an illegal construction. The two promoters have been arrested on charges of negligence. We are looking into the matter," the officer said.