Was it an accident or a fall?
The consequence of a failed CPR attempt after she was already found unresponsive or an intruder who broke in, picked up the girl and then dropped her again, or assaulted her before leaving without disturbing anything else?
Or, as the prosecution claim, was it a deliberate act from her father, who when tired and frustrated lashed out and struck his severely disabled nine-year-old daughter in the chest?
Or was it the girl's mother, who the defence claim had "equal opportunity" as her father, who may have "somehow snapped and assaulted her daughter"?
There was never any real question about the young girl's cause of death.
A forensic pathologist made a determination a few days after she was found dead in her bed on July 17, 2011, that the girl's direct cause of death was blunt force trauma to the upper abdomen and lower chest.
But how the girl sustained those injuries is an enduring unsolved mystery and now a question for a jury, who retired on Tuesday to begin deciding the fate of the girl's father, who cannot be identified and who has pleaded not guilty to manslaughter over her death.
The girl, who suffered from a severe form of cerebral palsy, weighed 15 kilograms at the time of her death and was unable to walk, talk or care for herself, the court has heard.
During their closing addresses, Crown prosecutor Steven Wilkinson and Public Defender Mark Austin ran the jury through the gamut of propositions, hypothesis and possibilities that could have caused the injuries that killed the young girl.
Mr Wilkinson dismissed as "mere speculation and conjecture" the possibility the girl had suffered an assault or a fall while under the care of respite workers in the days before her death or that an intruder entered the house and caused the girl's injuries.
"The Crown submits that the only rational inference that the circumstances would enable you to draw is that the accused, who admitted he was extremely tired, perhaps because of something that [the girl] was doing, that the accused lost his self-composure perhaps in frustration and it's the Crown case that he struck out at [the girl] and caused the injuries," Mr Wilkinson said.
Meanwhile, Mr Austin called the prosecution's circumstantial case "very weak" and stressed to the jury that it was their job not to solve the case, but to determine the man's guilt.
"You cannot, in my submission, be satisfied beyond reasonable doubt in relation to the guilt of [the girl's father] for the offence of manslaughter and a verdict of not guilty in these proceedings would not be an unsatisfactory outcome," Mr Austin said.