At least 21 people including several children have died after a bus crashed off a flyover near Venice and burst into flames, officials say.
The bus broke through a barrier and plunged almost 15m (50ft) near railway tracks in the district of Mestre, which is connected to Venice by a bridge.
Five Ukrainians, one German and the Italian driver were among the dead, city prefect Michele Di Bari said.
Venice Mayor Luigi Brugnaro said a "huge tragedy" had taken place.
"An apocalyptic scene, there are no words," he said on social media.
CCTV footage of the flyover from Tuesday night showed the vehicle driving past another bus, before toppling off the carriageway.
One rescuer spoke of a "tragedy of young people, if not very young people, except for a few adults".
Three children including a baby were among the dead, emergency services said. Interior Minister Matteo Piantedosi said that the toll could rise.
Fifteen people are known to have been injured, five of them seriously. Venice officials said they included Ukrainians, Austrians, Spaniards and other foreign tourists.
Among the injured were two 16-year-olds and two younger children, the local governor said.
Two German brothers, aged seven and 13, were being treated for broken bones in hospital in nearby Treviso. Their parents were killed in the accident and the boys were being given counselling.
The bus, carrying 39 people, crashed at around 19:45 (17:45 GMT) on Tuesday. It had apparently been rented by a local company to pick up tourists from the historic centre of Venice to a campsite in the nearby Marghera district.