Second twin dies after Sydney pool tragedy

The second twin pulled unconscious from a backyard pool in Sydney's northwest earlier this month has died.

Robbi and Charli Manago, aged 23 months, were found floating in the family’s Kellyville Ridge swimming pool by their distraught mother, Fleur, on December 20.

Sadly little Charli died in hospital on Boxing Day.

Little Robbi's parents had remained at his bedside throughout his nine-day fight for life.

But tragically for the family, Robbi was confirmed dead on Thursday.

The twins were the youngest of six children. Source: 7 News

Emergency crews at the scene. Source: 7 News

Paramedics had performed CPR at the scene before the twins were both airlifted to The Children's Hospital at Westmead under police escort.

Neighbour Michelle Skevington heard the twins' mother's screams and came running to help, desperately performing CPR on the unresponsive children as an ambulance was called.

"Had the inkling to yell over the fence 'are you ok?' when I heard the screaming," Michelle Skevington told 7 News at the time.

The family's backyard pool. Source: 7 News

Robbi and Charli with Santa. Source: 7 News

"I'm so pleased that my instincts said to me 'get over and have a look if they're ok'.

Police have checked the family's swimming pool fence and confirmed that it was adequate, but said the incident was a timely reminder for parents to be vigilant.