'I forgive him': Heartbroken parents speak after children hit by car

The heartbroken parents of two children killed when they were hit by a car in Sydney's south-west have spoken of their shock, saying they forgive the driver.

The parents of five-year-old Katherine and one-year-old Harry fought through tears as they spoke to reporters about the Wednesday afternoon crash near their Cabramatta home.

"I can't describe it, last night I couldn't sleep," their father Vundy Tha said.

"Even the driver, I forgive him already.

"Nothing can change, you know? Nothing can change. I couldn't get my kid back."

The 56-year-old driver of the vehicle has not been charged by police and was taken to hospital for mandatory testing after the crash.

Mother Sok Ram was walking with her daughter, who had just finished kindergarten for the day, and was pushing her son in a pram when the crash happened about 3:15pm at Joseph and Gilbert Street, Cabramatta.

"I'm not angry to the driver, you know, but he doesn't want to do that too," she said.

The children were treated on the scene by NSW Ambulance paramedics but died in hospital a short time later.

"Why my kid die? Why, please, I hope it hit me, not my baby," she said while being comforted by loved ones.

She said she felt "empty" after the loss of her two children.

"I don't want anything.
I want only my kids. My daughter, my son, my life," she said.

"I feel my life is success but now empty. Nothing, nothing to me now.
I can't do anything."

Mr Tha said the couple's daughter Katherine was "smart" and was due to get an award at school on Friday.

A NSW Department of Education spokesperson said support was being provided to affected staff and students of the school community.

"We are deeply saddened by the tragedy that has affected the local community and share their grief," the spokesperson said.

Family praises 'phenomenal' passers-by who lifted car

Ms Ram said she was thankful to the members of the community who helped try to save and resuscitate her children.

"I can't believe it, you know? That everyone, you know, a lot of people come.
I never seen it like that a lot," she said.

"Thank you for the community."

Mr Tha praised the efforts of several bystanders who he said lifted the car up to try and save his son and daughter.

"Thank you for everyone, I wasn't here, only one word for them: Appreciate them, thank you.

"Unfortunately I couldn't be there, they couldn't be saved."

NSW Police Superintendent Tim Calman had on Wednesday commended the "phenomenal" members of the public who provided assistance at the scene.

"We've had a number of motorists that have actually stopped and collectively have moved the vehicle onto its side, tipped it over in order to get one of the children from underneath the vehicle," he said.

"It's tragic circumstances for the family."

Police will prepare a report on their deaths for the coroner and the Crash Investigation Unit is looking into the circumstances leading up to the crash.