One child has been killed and two others injured in a crash outside a school in Carlingford.
Paramedics and police were called to Carlingford Public School at 9.20am on Wednesday to reports that a vehicle had been involved in a collision with a number of children.
One of the children, understood to be a six-year-old boy, died near the intersection of Rickard Street and Marsden Road, NSW Ambulance confirmed.
Two other children were treated at the scene and were taken to Westmead Hospital, one with minor injuries and the other as a precaution.
Police said two women also were taken to hospital. One was the driver of the vehicle, and the other was a relative of the dead child. Both were believed to be suffering from shock.
A female relative of the boy who was killed said he was in Australia on holiday from Malaysia.
She said her daughter-in-law was walking with her two granddaughters, his cousins, to school when he was struck.
The woman said her two grand daughters, aged 6 and 4, had been taken to hospital.
The father of the two girls involved in the accident, and the uncle of the boy killed, said one had a broken hip.
People at the scene who phoned triple-0 reported that parents were standing in the street, screaming.
One of the children initially was trapped under the vehicle, which is believed to have hit a wall.
Wednesday is the last day of the school year for students at Carlingford Public School, according to the school's website.
Police and paramedics said no further information was immediately available.
Helen Pendlebury, who runs the school's uniform shop and has grandchildren at the school, said children spent recess on the other side of the school so they wouldn't see the accident.
"They will be doing some counselling with the students," Ms Pendlebury said.
"Traffic is pretty crook of an afternoon, during pick up and drop off. It's pretty hectic. There's no public transport, so every child walks or gets dropped off or picked up.
"We never thought we would see something like this happen."
A mother, Magdalena Kowalska, said she had received a call from the school advising her the children were fine but she could pick them up if she wanted to.
Her 11-year-old son Alex said: "We were told a little boy died in a car crash. I was pretty sad about it. This is our last day of school."
Another resident, Gary Bennett, said the street was very dangerous around school opening and closing times as parents drop off their children.
"At 9am the cars are parked all the way along the street. Even driving out of your driveway, you can't see past the cars," Bennett.
"You can't see a car coming up the street so really it was something waiting to happen. It's just shocking."
Two parents, who rushed to the school after hearing about the accident on radio and television news, said they wanted to find out more information.
"It's just so sad," one of the women said.
A lady who lives across the road from the school said: "it was an accident waiting to happen".
A white four-wheel-drive, believed to have been involved in the crash, remained in the school's driveway and police have taped off Rickard Street. Police have covered the front of it with a blanket.
The mother of a child at the neighbouring daycare centre said traffic in Rickard Street was notoriously bad before and after school because of a lack of parking or speed bumps.
"This traffic is always a problem, it's so hard to find parking," said Hannah Shen.
"In the morning this street is terrible. [Drivers] don't care about the children, I'm always holding my kids tight. It's scary."
She said she saw a pregnant woman being carried away from the scene in shock afterwards.
"She was just saying 'The car hit the fence, the car hit the fence'," Ms Shen said.
It's understood the child was the cousin of a student at the school.
School teachers have been holding children together inside school grounds.
Police from Ryde local area command have set up a crime scene and are investigating.
A report will be prepared for the coroner.