A cyclist was airlifted to hospital after being involved in a crash with a bus in Halifax yesterday.
The collision happened shortly before 5pm at the junction of the A58 Rochdale Road and Pye Nest Road in Pye Nest.
The cyclist, a 49-year-old man, was seriously injured.
He was taken to Leeds General Infirmary by air ambulance.
A number of local road closures were in place while emergency services worked at the scene.
Now police are trying to piece together the movements of the cyclist and bus in the moments leading up to the crash.
A West Yorkshire Police spokesman said: "Officers are appealing for anyone who was in the area who may have seen the cyclist or the bus in the time before the incident, or who witnessed the collision itself to come forward with any information.
"They are also appealing for any passengers travelling on the bus journey who may have any information and not yet spoken to police to get in contact."
Contact PC Stuart Parkin at the Western Safer Roads and Neighbourhoods Support Team via 101, quoting 13170366425.