Two children remain in a serious condition in hospital after a theme park rollercoaster crashed 20ft off its tracks.
Ten people were initially taken to hospital after the Tsunami ride derailed and hit the ground at M&D’s amusement park at Strathclyde Country Park in Motherwell on Sunday afternoon.
Two boys, aged 11 and 12, are in a serious condition at the Royal Hospital for Sick Children in Glasgow, one with chest, abdominal and leg injuries and the other with arm and hand injuries.
Six others remain in hospital including a 19-year-old man with a knee injury, a 14-year-old girl with chest injuries and an 11-year-old boy with head and leg injuries.
Among those already discharged from hospital is a 25-year-old woman who was walking past the rollercoaster when the carriage plunged to the ground.
Officers are now investigating the crash with the Health and Safety Executive (HSE) and engineers are inspecting the Tsunami.
Detective Inspector John Malcolm said: “This is a really serious incident that has affected many people visiting the theme park.
“We have now launched a joint investigation with the HSE and our priority is to find out the cause of the incident.”
HSE principal inspector Barry Baker said: “We have brought specialists in mechanical engineering to the site to begin the process of finding out what caused the gondolas to come off the rails.”
A teenager injured in the crash has said she thought she was going to die. Katie McArdle, 19, said on social media she was discharged with a broken wrist while her boyfriend dislocated his knee.
Writing on Facebook, the student said: “I have never been so scared in my entire life. Honestly thought I was going to die, sitting in that carriage upside down with everyone screaming.”
The ride was full when it came off the track and police, firefighters and paramedics rushed to the scene as visitors posted images on social media appearing to show a mangled carriage on a pathway surrounded by dozens of people.
The grandfather of another victim praised doctors for saving his hand. Thomas Campbell said Liam Boyle, 11, went through eight hours of surgery.
Writing on Facebook, Mr Campbell said: “The good news is Liam’s operation has been a success, recovery will take a while but at least we know he’s going to be alright.”
It is not the first time M&D’s has had problems with its rides, including the Tsunami.