Police in West Yorkshire have launched an urgent appeal to trace a little girl who dialled 999 to say her mother was not moving.
The girl, who gave her name as Ellie, called the ambulance service to say her mum had fallen at their home in Leeds.
She said she was three years old and that her mother is called Stacey Hall.
She also told the 999 operators that her house number was 23 and had "Mount" in the street name.
She said her grandparents lived in Bridlington.
The call was made at 10.53am yesterday but despite extensive enquiries since then the police have been unable to identify where it came from.
Detective chief inspector Lisa Griffin, from West Yorkshire's homicide and major enquiry team, said: "We urgently need the public's help to identify exactly where Ellie and her mum are.
"We are hoping that someone out there who knows the family will recognise the pieces of information that the ambulance call taker managed to get from her and will get in touch.
"We are treating this situation extremely seriously as it appears we have a woman in need of urgent medical attention and a vulnerable little girl who will also need our help."
During the call, that lasted 33 minutes, Ellie told the call-taker she was nearly four years old and that her mum had fallen over and would not get up.
She said she had shouted at her mum and wiggled her but she remained on the kitchen floor with a piece of toast in her hand not moving.
She said the front and back door were locked and she could not get out of the house.
A team of detectives has been making wide-ranging enquiries to trace the family, including checks on police systems, hospitals, and the public register of births.
Anyone who thinks they know who Ellie and her mum Stacey Hall are and where they live is asked to urgently call the homicide and major enquiry team via 0800 056 944.
