A nine-year-old boy was fighting for his life in Ninewells Hospital in Dundee, after a car left the dual carriageway near Forfar, flew 20 feet down an embankment and flipped over, landing on its roof in a field.
Four people, all travelling in a blue Ford Focus, were hurt in the accident on the A90 Dundee to Aberdeen Road near to Birkenbush on Thursday night, and all were taken to Ninewells.
The 39-year-old woman driver was trapped in the vehicle for 40 minutes.
Fire fighters had to use hydraulic cutting gear to free her from the wreckage. She suffered back injuries.
A 17-year-old girl and a 19-year-old man were treated for minor injuries and were discharged from hospital.
A passing motorist said it looked as if the car had “flown” over the roadside crash barrier as it was not damaged.
The car had travelled a further 30 yards before coming to rest upside down in the field.
No other vehicle was involved.
The accident, which happened around 7.30, closed the northbound carriageway for several hours.
Police set up a diversion.
A trauma team from Ninewells rushed to the scene along with two ambulances and two fire appliances.
Last night police said the boy, a back-seat passenger, sustained serious and potentially life-threatening injuries.
A spokesman for the Tayside force appealed for anyone who witnessed the crash to contact them on 0300 111 2222.