Police are appealing for witnesses after a 34-year-old man suffered suspected spinal injuries when a car overturned near to Chorley.
Two other people suffered minor injuries in the accident, which happened at around 9pm on Sunday, May 14 on Rivington Road, say police.
Detectives say that a Peugeot 106 left the carriageway and overturned down an embankment before coming to stop.
A 34-year-old man from Chorley suffered suspected head and spinal injuries and was taken to Salford Royal Infirmary for treatment.
Two other people, a male aged 17 and a woman aged 33, both from Chorley, were treated for minor injuries.
Police are appealing for information and are urging anyone who witnessed the incident to contact officers.
Sgt Tracey Ward, of Lancashire Police, said: “Three people have been injured – one seriously – following a road traffic collision close to Chorley.
“We would urge anyone who can assist with our enquiries to come forward.
“We are particularly keen to speak to anyone who saw the vehicle before the collision or witnessed the incident.”
The road was closed for three hours while accident investigators attended the scene.
Anyone with information can contact police on 101 quoting 1527 of May 14.