A father has spoken of his life being torn apart by a crash that killed his young son and fiancee.
Damien Wallace lost Jack, 4, and Jack's mother Lisa, when their vehicle was struck by a decoupled BP petrol tanker on August 7, 2014.
The incident occurred in the morning, but Mr Wallace didn't find out until hours later after hearing of the crash and being unable to call his partner.
He had frantically tried to reach her on her phone while at work from about 9.30am.
"I kept trying to call Lisa over and over again," Mr Wallace said in his victim impact statement, which was read out by prosecutor Andrew Palmer QC in the County Court on Thursday.
"I rang her work to find out if she'd arrived, they said no, so I rang Jack's daycare centre and they also told me that he hadn't arrived.
"I started getting a bit frantic so I contacted the Wodonga Police Station and asked them if they could give me any details about if Lisa, Jack or our vehicle was involved in the collision.
"They said they didn't know details."
He kept trying to call his partner, their neighbour, and police, before driving to his parent's house in Thurgoona in southern NSW.
A police officer, who was clearly emotional and struggling to say what had happened, delivered the devastating news about 2pm.
"I couldn't believe it had happened," he said.
"I asked the police officer three or four times if it was true.
"I just couldn't believe that my son Jack was dead as well."
Mr Wallace went into shock.
He can't remember much else of the day, which left his extended family shattered.
"We just had no idea what to do," Mr Wallace said.
"We didn't have any help, or anyone to guide us through the process."
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Mr Wallace eventually went to the Wodonga Baptist Church on Melrose Drive to make funeral arrangements.
The pair were farewelled in the same coffin by 1000 mourners 13 days after the incident, with balloons released in their memory.
Peta Cox also died in her vehicle during the incident, which occurred on the Wodonga Yackandandah Road at Staghorn Flat.
Wodonga business Heavy Mechanics serviced the truck and trailer dozens of times before the decoupling, and failed to detect wear in the components.
It's shocking to think that was on the road ... it was grossly incompetent- Prosecutor Andrew Palmer
Mr Palmer said their servicing of the coupling had been "grossly incompetent".
"This is a critical component, as the terrible accident showed," he said.
"If this fails the trailer decouples and can kill people.
"If there's any doubt for a $300 part that takes half-an-hour to an hour to replace, where BP are happy to pay the money, you wouldn't take a one-in-a-thousand chance."
Mr Wallace has been unable to work since the tragedy.
He struggles to get out of bed some days, developed rashes in the lead up to the many court dates over the incident, and moved town to get away from the attention.
At one point, he told his mother not to come into his home if there was a note left on the door and to instead call police.
He struggles to go to places he visited with his late family.
"I'm just angry about the whole incident," Mr Wallace said.
"Whenever I have good memories about them I also remember that they were killed for a $300 part and because mechanics didn't do their job properly.
"Jack was a complete innocent - he was only four years old.
"Not long before the incident, Lisa and I had enrolled him in school and he never got to experience that.
"There are so many things he will never get to experience.
"Jack won't get to grow up, get a girlfriend or make a life for himself.
"Jack was a well behaved, loving and caring child.
"Lisa was a wonderful person, she was a great mother and was caring and very kind.
"It's horrible for me to know we will never get to watch Jack grow up and that Lisa will never get to be a grandmother."
He has another partner and children who ask about Jack.
"I have to explain that he's died and they will never meet him," Mr Wallace said.
His oldest son is now four - a tough age for his dad who fears his family will be taken away again.
"I think, what if they don't come back," he said.
"They say time heals all wounds but when the wounds are as deep as these, I don't think they'll ever be healed."
Mr Wallace's mother, Liz, said she had lost her family, including her son.
"It all could have been avoided," she said.
"I want my son back the way he was.
"This nightmare never ends."
She dropped 30 kilograms of weight after the incident, had panic attacks, was unable to sleep and has struggled to get into cars.
Gerry Turner said the loss of his daughter and grandson would be with him for the rest of his life.
"What makes it hard, you knew it wasn't an accident," he said.
The County Court on Thursday heard submissions on sentence for the Wodonga business and the ability of the company to pay a fine.
Mr Palmer argued the company had completely disregarded signs of movement in the components that failed.
"It's shocking to think that was on the road ... it was grossly incompetent," Mr Palmer said of the rig.
"That coupling speaks for itself... there can be no doubt in my submission that the method of servicing adopted by Heavy Mechanics was not just a different way of doing it, it was grossly incompetent and they should have known better and they should have paid attention to the very obvious signs of wear."
Defence lawyer Daniel Gurvich QC tendered a large number of references on behalf of the business, which is owned by Keith Haire and has four employees.
The company had not had any improvement or prohibition notices from WorkSafe before or after the incident.
"This is not a case where there was a blatant disregard for safety," Mr Gurvich said.
"This is not a case where there was a deliberate overriding of a safety mechanism or a safety method."
He said Mr Haire had given evidence that the nut, which holds the truck and trailer together, was tight when it was serviced.
He noted there had been lengthy delays in the case and said the business had an "impeccable" record after the offending.
The matter will return for sentencing at a date to be fixed.
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