Injured people lay on the pavement, recalling recent terrorist attacks by vehicles mowing down pedestrians, but there was no indication that the Copacabana incident was deliberate.
The G1 news website reported that the driver, who fled the scene but was quickly arrested by police, had said he had had an epileptic fit, and medicine for epilepsy was found in the car.
Copacabana police confirmed the baby’s death and said 15 injured people were being treated in hospital.
Witnesses said on the Globo News network that the car had driven over a cycle path and across the promenade, hitting people and crashing through tables and chairs, before stopping on the sand of the beach. The smashed widescreen and dented roof indicated the force with which the vehicle had hit people.
The promenade at Copacabana is a favourite summer evening walk for Rio residents and tourists who have started to arrive for carnival celebrations next month.