Councilman Elias Jr said he never expected the bridge to actually collapse when he was there and was “in shock”.
Eight cars, including three trucks with chemicals, plunged into the river.
People in the towns of Estreita and Agia Annapolis, on both sides of the river, were told to avoid collecting water from it.
Rescue operations are carried out from boats. Four bodies were found, including the female driver of one of the trucks and an 11-year-old girl, the fire department said. On Sunday, one man was rescued alive from the water.
The Juscelino Kubicek de Oliveira Bridge – more than half a kilometer (1,600 feet) long – was built in the 1960s and is the main link between the two states across the Tocantins River.