William Tyrrell's foster mother has told a coroner she immediately thought "someone has taken him" when the NSW town of Kendall fell quiet and the three-year-old boy vanished without a trace.
"I couldn't hear a thing. It was silent, there was no wind, there were no birds," the woman said in Sydney on Tuesday at an inquest into William's disappearance and suspected death in September 2014.
Counsel assisting the coroner, Gerard Craddock SC, asked: "In your experience, that little part of this little village, sound carries pretty well?"
"Oh, unbelievably. You can hear everything," the foster carer replied.
She said she was left standing in the backyard of her mother's house on the mid north coast wondering why she couldn't hear William or see him in his red Spiderman suit because "it hasn't been that long".
He'd been playing "daddy tiger" and roaring at the two women.
"My immediate thought was somebody has taken him and he's gone," she said.
The woman, who cannot be identified, had a blue-and-red "Where's William?" ribbon pinned to her chest as she sat in the witness box giving evidence.
On Monday, she testified having seen three cars on the street the morning he disappeared - including one white and one grey car parked between two driveways.
The woman on Tuesday said she didn't realise until after William went missing that those two cars were gone.
"I know in hindsight that they weren't there but whilst I was searching I didn't. In the initial stage, it didn't even occur to me that those cars weren't there," she said.
Mr Craddock said he expected the evidence before the inquest would establish William "was taken" and his disappearance "was the direct result of human intervention".
The first week of hearings will explore William's foster and biological families, when he disappeared and the action taken shortly after he went missing.
Family members, neighbours and police will give evidence.
Further hearings will be held in August when persons of interest will be called to testify.
The inquest before Deputy State Coroner Harriet Grahame continues.