Four teenagers were injured - three of them seriously - when their car came off the road and crashed into trees.
Firefighters had to free the boys from the car on the Broughton to Appleby road in North Lincolnshire on Sunday.
A 16-year-old boy from Winterton suffered serious head and neck injuries and was taken to Hull Royal Infirmary.
The 17-year-old driver from Scunthorpe suffered a head injury, a 17-year-old Winterton boy had a broken arm and a 16-year-old Dragonby boy suffered cuts.
Police are appealing for witnesses and want to hear from anyone who either saw the red Vauxhall Corsa come off the road or saw it before the crash.