A motorway bridge has collapsed in the northwest Italian city of Genoa and fire brigade sources say 35 people were believed killed as vehicles plummeted to the ground.
Dramatic video footage captured the moment of the disaster when one of the huge supporting towers crashed down during torrential rain.
Vehicles and debris fell 45m (148ft) on to rail tracks, buildings and a river.
Rescuers are trying to free people caught in crushed vehicles or rubble.
Fears that other parts of the bridge might fall have prompted the evacuation of buildings in the area, a rescuer told Italy’s Ansa news agency.
Interior Minister Matteo Salvini promised that anyone found to be responsible for the bridge collapse would be held to account.
“I have crossed that bridge hundreds of times,” he said. “Now, as an Italian citizen, I will do everything to get the names and surnames of the managers responsible, past and present, because it is unacceptable to die like that in Italy.”
A representative of the motorway’s operator, Autostrade, told Reuters news agency there had been “no reason to consider the bridge was dangerous”.
Shares in Atlantia, Autostrade’s parent company which runs much of the country’s motorways, fell 6.3% after news of the collapse.
Prime Minister Giuseppe Conte is due to visit the scene to support the search-and-rescue effort and show solidarity with the victims and their families, his office said.
The Morandi Bridge, built in the 1960s, stands on the A10 toll motorway, which serves the Italian Riviera and southern coast of France.
The missing section was dozens of metres in length, and ran across the span of the Polcevera river.