ONE of the teenagers seriously injured in last week's Alton Towers rollercoaster crash has had her left leg amputated above the knee, doctors have confirmed.

The news emerged as Poole-based Merlin Entertainments opened the theme park for the first time since last week’s accident.

Leah Washington, 17, from Barnsley in South Yorkshire, also suffered a fractured hand in the incident, which left four people with serious injuries and 12 others hurt.

Leah's boyfriend, 18-year-old Joe Pugh, was treated for two broken knees and extensive hand injuries, the University Hospitals of North Midlands NHS Trust has confirmed.

Alton Towers had been shut since a car on the Smiler ride crashed with an empty car last Tuesday.

David Washington, Leah's father, said medics "saved Leah's life" following the crash, after which she was said to have been given a blood transfusion and morphine before she passed out.

In a statement, he said: "We would like to thank our family and friends and all the well-wishers for their support.

"Leah has suffered a life-changing injury and now has many months of rehabilitation ahead of her.”

Leah, her boyfriend Mr Pugh, 27-year-old old hotel assistant manager Daniel Thorpe from Buxton in Derbyshire, and 20-year-old Vicky Balch from Leyland in Lancashire, have been described as the most seriously injured.

Ms Balch suffered potentially life-changing injuries in the crash, and is expected to make a "substantial claim for damages" to support her recovery, her solicitor said last week.

The four are being treated at the Royal Stoke University Hospital and the University Hospital Coventry.

Nick Varney, chief executive of Merlin Entertainments, which is based at Market Close, Poole, has said the group was adding "another layer" of safety measures to existing rides as a "precaution" against the prospect of another accident.

Merlin has temporarily shut another Alton Towers ride, Saw, a similar rollercoaster at its Thorpe Park site, and two rides at Chessington World of Adventures to "reinforce the safe operation" of the attractions.

Mr Varney said: “I want to be able to look everybody in the eye and promise them when they come to our parks and get on our rides that they are safe."