The fire department did not immediately respond for confirmation of the toll.
The flooding followed dramatic rainstorms overnight accompanied by lightning and high wind. Residential streets, including in impoverished favelas, were inundated and a stretch of the coastal cycling path built ahead of the 2016 Rio Olympics collapsed.
Major highways were partially blocked, leading to traffic jams.
Authorities said that in the west of Rio, the rain usually expected for the whole of February fell in one night.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)