Rail accident specialists are continuing their investigation into a Sheffield tram-train crash, which happened on its first day of service.
Four people were injured when the tram-train crashed into a lorry carrying gas canisters at the junction of Woodbourn Road and Staniforth Road at around 3.30pm on Thursday.
The tram-train was travelling from Parkgate into Sheffield city centre when the collision happened, having only welcomed passengers for the first time earlier that day.
South Yorkshire Police said no arrests had been made following the incident and added the investigation had been passed to the Rail Accident Investigation Branch (RAIB).
Stagecoach Supertram, who operate the service, have requested specialist engineers from manufacturer Stadler, based in Spain, assess the damage to the vehicle.
The company said its timetable was not affected following the incident.
Passengers said the tram-train lifted around 1m in the air before derailing and landed around 6m to the left of the tracks.
Steve Barber, vice president of the Light Rail Transit Association, who was on board at the time of the crash, said the vehicle was travelling at around 20mph when the collision took place.
The pilot project was orginally due to be operational in 2015 at a cost of £15 million. It launched almost three years late at a total cost of £75 million.
Steve Barber, vice president of the Light Rail Transit Association, who was on board at the time of the crash, said: "I was sat in the front seat of the tram and we were approaching the junction and all I saw was a lorry in front and then the bed of it hit the tram.
“The next minute we were up in the air and my back went. The windows were all smashed and we landed about 6m to the left of the tracks."
In a statement, the RAIB said it was aware of the incident and was making initial inquiries.