A four-year-old girl who died had been found unresponsive in the bath after suffering a suspected cardiac arrest, an inquest opening has heard.
Police received a call from the ambulance service requiring assistance to help Cali Marged Lewis-Mclernon at her home in Llangunnor, Carmarthenshire, at 17:59 GMT on 20 February.
She was taken to West Wales General Hospital but died at 02:45 the following the day, the inquest at Llanelli Town Hall heard.
A 41-year-old woman was arrested on suspicion of gross negligence manslaughter and has been released on bail, Dyfed-Powys Police said, as investigations into Cali’s death continue.
A post-mortem examination took place at the hospital on 28 February, but results are awaiting further investigation.
Paul Bennett, acting senior coroner, shared his condolences with the girl’s family.
The inquest was adjourned until 30 June as the medical cause of death and police inquiries continue.
