Seven people have been pulled alive from under the debris of the caved-in house, deputy police commissioner Pushpendra Kumar told CNN. They have been hospitalized.
The collapse snapped electric cables, causing power outages in the neighborhood.
Several people were feared trapped in the rubble, which emergency crews were trying to clear, Kumar said.
The multifloor building was located in a congested western district of New Delhi, pockmarked with ramshackle residential blocks.
The cause of the collapse was not immediately known. It was a rainy day in the city.