Five teenagers have been injured after their car left a Lancashire bypass and ended up on its roof.
The black Vauxhall Corsa crashed on the northbound carriageway of the A56 at Accrington at 2330 GMT on Wednesday.
The driver and two back-seat passengers were taken to the Royal Blackburn Hospital to be treated for serious head injuries. Two other passengers suffered minor injuries.
The road was closed for four hours while police investigated.
Police said that the car overturned and travelled a further 250m before coming to rest on its roof in the second lane of the carriageway.
The 17-year-old male driver, a boy, 16, and a girl, 17, are in a serious condition.
Two other 16-year-old male passengers have been released from hospital.
The victims are from Accrington and Blackburn.
Police said a second black Vauxhall Corsa was driving along the same stretch of road at the time of the incident.
Sgt Pete Sculpher, of Lancashire Police, said: "I would also like to speak with anybody who may have seen either or both Corsas being driven along the A56 prior to the incident.
"A full investigation into the cause of the collision is now under way."