“I thought it was an earthquake. I was sitting down and I fell on the floor, along with the other passengers,” one man told Ansa news agency. “It was terrible.”
As it left the track, the tram apparently first hit a traffic light before smashing the window of a restaurant. A delivery rider waiting at the traffic light and a young man on a pavement narrowly escaped injury, La Repubblica website reported.
“I got on at the first stop, [Piazza della] Repubblica,” one female passenger told Corriere della Sera. “I was standing next to the driver, and they all crashed into me.”
“I just heard an enormous bang,” said 27-year-old Anna, who was in an office nearby, quoted by AFP. “I saw a bit of the tram had gone into a shop.”
Civil protection teams have set up a tent at the scene to help the injured.
It is not clear what caused the derailment, although media reports suggested the tram had taken a sharp corner too quickly, as it turned out of Viale Vittorio Veneto.