Part of a bridge over Brazil's Moju River collapsed early Saturday, after a ferryboat collided with a bridge pillar.
Two cars were seen plunging into the river, but it's unclear how many people were in the vehicles with scuba divers searching the river.
The five crew on the ship are said to have survived.
The bridge, which connected one of the country's busiest ports, will potentially affect shipment of grains.
Pará governor Helder Barbalho has signed a state of emergency after the accident.