British Formula 4 driver Billy Monger has been airlifted to hospital following a high-speed crash at Donington Park in Leicestershire.
The 17-year-old ran into the back of another car being driven by Finnish driver Patrik Pasma, which appeared to have stopped on the track.
The teen remained in the vehicle for over 90 minutes after the crash and he is said to have suffered leg injuries.
Footage of the incident was captured by his onboard camera.
In a statement, the organisers said: "Monger has been carefully extracted from the car after suffering leg injuries, and has since been airlifted to the Queen's Medical Centre in Nottingham for further examination.
"Pasma was also carefully extracted from his car. He was fully conscious and immediately taken to the on-site medical centre. He has since been taken to the Queen's Medical Centre for further assessment.
"Further information will be provided in due course."
The Formula 4 British Championship is a motor racing series which features a mix of professional motor racing teams and privately funded drivers.
It is designed as a low-cost entrance to car racing, and is aimed at young racing drivers moving up from go-karting.
It replaced the British Formula Ford Championship in 2015 - a series in which successful Formula 1 drivers such as Ayrton Senna and Jenson Button won their first single-seater titles.
Update: Billy Monger has lost both of his lower legs after the horrific crash. Please click here if you are interested in making a donation to fund the care, treatments and therapies required by Billy in the immediate future and going forward, helping him to return to a full and active life.
For more information, please visit BBC.com.