Two men and two women have been arrested.
Police have launched a murder investigation following the death of a woman in Birstall.
Officers were called by paramedics to a flat off Raikes Lane, Birstall at about 00:05am early on Friday morning to a report of an assault on female.
On attending they found a 19-year-old female who was none responsive. Despite medical attention by paramedics she died at the scene.
Following enquiries, officers arrested two men aged 20 and 19 and two women aged 23 and 17 on suspicion of murder.
All four remain in police custody for questioning.
Detective Superintendent Jim Griffiths of the Homicide and Major Enquiry Team, said: “Police are continuing enquiries into this incident this morning and have launched a murder investigation.
“We continue to question four persons who remain in police custody in connection with the death."