A ferryboat has collided with a bridge in Brazil's northern state of Pará, plunging a 200 metre (657ft) section into the Moju River, ONA reports citing BBC.
Witnesses said two small cars fell into the water after the ship crashed into one of the pillars.
It is unclear however how many people have been hurt and scuba divers are searching the river. The five crew on the ship are said to have survived.
Pará governor Helder Barbalho signed a state of emergency after the accident.
"Our priority is searching for victims and giving complete support to their families," he told state media.
Mr Barbalho posted footage of the 860 metres-long collapsed bridge on Twitter.
The bridge in the country's Amazon region lies en route to one of Brazil's busiest ports, Belém.
Authorities are working to clear debris from the river and have set up a number of barges to ferry residents across the water until it can be fixed, while placing warning signs on pillars of other bridges nearby.
Local media reportedly said an inspection of the bridge earlier this year revealed corrosion on the pillars. While the government requested emergency funds to fix the problem, it reportedly did not consider the issue serious enough to close the route.
Civil police are investigating whether the ship was officially registered, the Associated Press says.
Authorities told Reuters news agency the collapse could affect shipments of produce through northern ports.
In 2014, a vessel collided with the pillar of another bridge nearby, causing about 50 metres to collapse into the water.