A young mother in her early 20s died in a car crash on Sunday afternoon.
The accident happened at 3.32pm on Boothtown Road, Halifax, close to the junction with Chester Road, and left several more people in hospital - including two children aged four and seven.
A Vauxhall Astra was travelling from Chester Road, crossing the A647 Boothtown Road to go onto Woodlands Road, when it was involved in a collision with a black Seat Leon travelling on Boothtown Road towards Halifax.
The front seat passenger of the Astra - a 25-year-old woman from Halifax - was pronounced dead at the scene. The male driver, aged 26, and two passengers – a girl aged seven and a boy aged four - were taken to local hospitals and are said to be seriously injured.
The air ambulance was called to take one of the casualties to hospital.
The occupants of the Seat Leon - four men aged 19, 20, 21 and 27 from the Bradford area - have been arrested on suspicion of causing death by dangerous driving.
Police say they are interested in tracing the driver of a blue X-registered Mercedes that was seen to be driving with the Seat Leon before the collision.
Anyone who witnessed the incident or the moments leading up to it or anyone with any information that could assist the investigation is asked to contact officers on 101.