A Western Australian family moved to Perth when a young mother and her 10-year-old son were killed and her three other children were injured during a "catastrophic" truck accident in the wheat region of the state.
Amy Slater, 26, and her son Leroy could not be resurrected after a semi-trailer crashed into their parked Holden Commodore on the Brookton-Corrigin Road near Corrigin around midnight
The three other children of Slater – two sons, Jacob and Thomas, eight and five years old and a three-year-old daughter, Madison – were transferred to the Perth Children's Hospital in a serious emergency after the accident.
The five-year-old child remains in a critical condition with life-threatening injuries, but it is expected to survive while the other two children have sustained minor injuries.
The car, which had pulled a trailer, had no petrol left and the 27-year-old father of the children had left to walk to Corrigin to get fuel.
The police said a semi-trailer, which was controlled by a 46-year-old man who transported grain, made a turn and collided with the parked car.
The collision caused both the Commodore and the trailer to be thrown into a nearby paddock.
After the crash, the police found the father along the Brookton-Corrigin Road about 9 km from the site.
Slater's emotional aunt, Pauline Bropho, told reporters that the family – who had just received a house transfer – had been looking forward to moving to Perth.
"Amy was an excellent mother to her children, everything she did was entirely for her children," she said.
"Little Leroy, he was a sweet little boy, loved his sport and he was looking forward to sporting in Perth here once they had moved.
"Amy waited years for this transfer to come to Perth to start a new life for her children … She was looking forward to the move and now she is gone and we do not have her anymore.
"We just want justice for her and her little boy who lost them … If the driver of the truck is guilty, we want justice for Amy and her baby."
Chief Inspector Ian Clark of the Great Southern Police District said the incident is a warning for motorists to pay more attention to driving in the country.
"The scene was pretty catastrophic with a fully loaded truck crashing against a car," he said.
"We really hate seeing something like that, it's a terrible situation in general, it's one of those things with crashes, sometimes you just can not believe people survived.
"It is a terrible tragic thing for the Corrigin community.
"We ask people when they are driving in the country, think of fatigue, think about consciousness, what is happening around you, just because people drive in the country, do not think things can not happen.
President of the Shire of Corrigin, Lyn Baker, told reporters today that the incident is "absolutely shocking".
She also said that the local community will come together to support the affected family, the volunteer aid workers who were present and also the truck driver.
"It is a time when the whole community must meet and certainly support the family, but also those volunteers who have put themselves at risk," she said.
"As far as the city is concerned, we are built on volunteers and the fire brigade and rescue troops who went to the accident and the people of the St. John Ambulance are all volunteers and so I can not imagine how that would affect them.
"For everyone who attends such terrible accidents, there must be a lasting effect, which people will certainly need our support.
"It is a shock for everyone in the city and it will certainly affect the school children (who follow lessons with the affected children).
"The children are well taken care of, of course the (school) employees who have worked with this boy for a long time will be supported."
9NEWS understands that the family involved in the accident has lived locally in Corrigin for the past five years.
The local school attending the children, Corrigin District High School, is also aware of the incident and support staff and psychologists will speak with their classmates.
More than one kilometer of the Brookton-Corrigin Road is closed, because large crash researchers are investigating the scene.
Mrs. Baker said in the 41 years that she lived in Corrigin, there have been many fatal accidents on the road and admits that more could happen in the future.
"The worst thing is that we know it will happen again," she said.
"There have been many … nasty accidents and loss of lives, I do not know that there is a silver bullet to prevent that."
© Nine Digital Pty Ltd 2018