Toddler dies, twin brother in critical condition after being found unconscious in pool.

A toddler has died in hospital nearly a week after she and her twin brother were found unconscious in a pool in Sydney’s north-west.

The 23-month-old boy and girl were pulled from the backyard pool of a Kellyville Ridge home last Tuesday night.

The toddlers were taken to Westmead Children’s Hospital where they remained in a critical condition until earlier today when the young girl died.

Police said the children were out of their parents sight for only a short time and that the pool met all safety requirements.

The girl’s twin brother remains in a critical condition and continues to undergo treatment.

A report is now being prepared for the coroner.

This post originally appeared on ABC News.