A baby was killed and at least 15 beachgoers were injured when a car ploughed into the famed beach at Copacabana.
The driver apparently lost control of the car, which shot over a cycle path and onto the pavement, through the crowds, before stopping on the sand of the beach.
Injured pedestrians lay sprawled out on the ground, echoing recent terrorist attacks by car, but there was no indication that the incident was deliberate.
Local media said the 41-year old driver was detained by police.
He claimed to have suffered an epileptic attack behind the wheel. Epilepsy medicine was found in the car.