Rescuers used sensors and life detectors to search for five other people who were feared trapped in the debris of the building in the Sion area of Mumbai, said Vijayendra Dahiya, an official at the National Disaster Management Authority.
Six others were injured when the structure caved in Monday night. Police cordoned off the building fearing more of it could collapse.
Building collapses are common in India as builders try to cut corners by using substandard materials, and as multistory structures are built with inadequate supervision.
Dahiya said the cause of the collapse was not immediately known.
In April, 74 people were killed when an eight-story building being constructed illegally in the Mumbai suburb of Thane caved in. It was the worst building collapse in the country in decades.
The massive demand for housing around India's cities and pervasive corruption often result in builders adding unauthorized floors or putting up illegal buildings.