A man suffered serious head injuries after the van he was a passenger in collided with a tree and a car, police said.
Officers are appealing for witnesses to the collision on Burnley Road, Halifax yesterday at around 3.15pm.
A Vauxhall Combo van was travelling towards Halifax before it collided with a tree and then a parked Vauxhall Insignia, officers said.
The 28-year-old man passenger of the van sustained "serious head injuries" and was taken to Leeds General Infirmary where he remains, they added.
Any witnesses or people who saw the van immediately before to the collision is asked to contact PC 1819 Baron on the non-emergency number 101, quoting log 1085.