A nine-year-old girl had wanted to go to her school disco but her father insisted she ride with him on his new dune buggy before it rolled over and killer her, a court has heard.
Crown prosecutor Andrew Tinney, SC, told the County Court on Monday that Ricky Stephens, 40, had just bought the buggy and wanted to take it for a drive around a paddock near his Yarra Glen property.
Stephens, who had never before driven a buggy or anything similar, took his daughter, Sophie, 9, and stepson, Cameron, 11, for a drive on the left-hand drive Arctic Cat Wildcat 4WD all-terrain vehicle fitted with driver and passenger bucket seats.
Sophie was seated unrestrained between her father's legs when he attempted to do a burnout, lost control and the buggy rolled over just before 6pm on September 6, 2013.
Sophie was thrown from the buggy and struck by the vehicle as it rolled. She died at the scene while Cameron suffered minor injuries.
When police arrived, Stephens, who pleaded guilty to one count of dangerous driving causing death and one count of reckless conduct endangering life, was calling out, "what have I done? What have I done?"
In an interview at Lilydale police station, Stephens told police he and the children had been "pretty eager" to get out and take the buggy for a drive.
He said he was driving over a mound of dirt and "I went to just give it a bit of a bucketful to make it spin out a little bit and as it done that, it just bit into the grass and just went into like a slow motion flip over".
Stephens told police no-one was wearing a helmet even though he was usually very strict about that sort of thing. "I just let my guard down tonight," Stephens said.
When asked if there was a reason he didn't think about seatbelts on the night, Stephens said he was eager to start driving and the decision would cost him for the rest of his life.
He told police the children were "laughing and just having a wow of a time".
Questioned as to why he had performed multiple burnouts, he said, "just because the kids were excited". He was estimated to have been driving at 34km/h when the buggy rolled over.
In an emotional victim impact statement read to the court, Sophie's mother, Tanya Exton, said her daughter had been the couple's "miracle" baby after being born three months premature and she had grown up to be a gorgeous young lady.
Ms Exton said Sophie had wanted to go to her school disco that night but Stephens insisted she stay with him because riding on the buggy would be more fun.
She said the image of Sophie's tiny lifeless body lying next to the buggy towering over her after the accident was something she saw every time she closed her eyes.
Ms Exton said Stephens, whom she married in 2006 before they separated six weeks later, had had just one job to do and that was the make sure his daughter was safe.
Defence barrister George Georgiou, SC, told the court Stephens did not intend to kill his daughter but accepted full responsibility for her death.
Mr Georgiou said Stephens had been seeing a "spiritual reader" to help him deal with his grief, his profound remorse and feelings of guilt.