Mother Julie Bullock, 49, and her son Hudson, 7, died tragically while Sienna, 7, suffered critical injuries after a car crossed onto the wrong side of the Hume Highway and collided head on with the family making their morning trip to Wollondilly Anglican School.

A witness who spoke to The Daily Telegraph described how he was holding Hudson, along with other drivers who had rushed to his aid, when he lost consciousness.

Emergency service crews tried desperately to revive the boy but he was pronounced dead on arrival at Liverpool Hospital.

He described the awful moment he saw a silver Holden Astra, travelling north, smash into the Mazda 4WD heading in the opposite direction near Wilton in south-west Sydney.

“We were trying as hard as we could to keep the little boy alive and awake but he went unconscious on us. There was nothing we could do,” the witness told The Daily Telegraph.

“There was also a nurse who just happened to be driving by and she tried her hardest.

“A silver car carrying one woman was driving north and it had come across through the grass median strip to the other side of the road and collided with a car carrying the mother and her two children.

“Both cars were absolutely totalled.

“I was on the phone with the ambulance operator. Some of the guys who had stopped to help jumped down and cut the kids out because they were both trapped upside down.”

“A truckie pulled off the dashboard because the mum was trapped, to try and pull her out. She then crawled out by herself and laid beside the car and people were giving her compressions until the ambulance got there.”

“The boy told us it was his twin sister. I’d like to go to the little boys funeral.”

Sienna remains in a critical condition at the Children’s Hospital Westmead while the 49-year-old woman, driving the Holden Astra is being treated at Liverpool Hospital and is also in a critical condition.

Speaking with The Daily Telegraph, Wollondilly Anglican School headmaster Stuart Quamby paid tribute to the family and said the accident had rocked the close knit community.

“The kids were and are very well loved by the community and the school,” Mr Quamby said.

“He (Hudson) was a great little kid and his sister (Sienna) is a terrific kid as well.

“The family are well known and well-loved, not just in the college community but in the wider community as well.

“It is going to be tough because there is will be a lot of hurt in the community because we are a small community out here, it is a country community.”

Mr Quamby said the school was offering counselling to students and members of the school community and it was available to anyone who wanted it.

This last tragedy on our roads takes the statewide road toll to 53 so far this year and follows on from a horror 2016 where 384 people lost their lives on our roads.