Six children were among nine people taken to the Royal Lancaster Infirmary after a crash between a school bus and a lorry.
The hospital took the majority of casualties after the collision on the A685 at Grayrigg, a village near Kendal, Cumbria, at 8.25am on Monday.
Police said the lorry driver, aged 44 and from Kendal, was airlifted to the Royal Preston Hospital with serious head, arm and neck injuries after firefighters freed him from his cabin.
His condition, although serious, was not thought to be life-threatening, Cumbria Police said.
The bus driver, a 47-year-old man from Kendal, was arrested on suspicion of driving his vehicle dangerously and later bailed pending inquiries.
It was carrying 24 children aged between 11 and 18, plus four adults.
A spokesman for North West Ambulance Service said those treated at the RLI included one adult with a head injury, another with rib injuries and another with neck pain. He said the six children suffered minor injuries in the accident.
The four adult passengers were a man aged 61 from Devon, a woman aged 44 and from Tebay, a 23-year-old woman from Tebay and a woman, aged 80, from Shap.
A spokesman for University Hospitals of Morecambe Bay NHS Foundation Trust, which runs the RLI, said the hospital had been prepared for ‘all eventualities’ after the initial report of the crash, but said major incident plans did not need to be used.
Cumbria Police have urged witnesses to the collision, which closed the road all day, to contact them on 101.