William's foster-mother, who cannot be identified due to a suppression order, was one of the last people to see the child. "I was driving to Port Macquarie Airport to collect a family member, and had this flash of [realisation that] there were two cars," she said, adding she had forgotten about them in the panic of William's disappearance. "I just went, 'There were two cars there.' My heart just sank because I thought those two cars were there for both of them," she said. "I got back to the house, I went straight down to the command post and I told the guy on duty. He gave me his phone and said search for the cars," she said. It was "odd" to see cars parked on the quiet street, which had long driveways that were typically used by visitors, she said.

Loading She did not get the number plates, because the cars were not significant to her at that time she said tearily. "I can't tell you how much I rack my brain over the number plates; I beat myself up," she said. On the morning he disappeared, William was dressed as Spider-Man, climbing trees and "pretending to be a daddy tiger", she told the inquest. She had just made herself a cup of tea when she realised the little boy had gone quiet.

"We heard him roaring around the garden and then I thought, 'Oh I haven’t heard him, I better go check on him, and couldn’t find him,' " she said. William Tyrrrell's grandmother. Credit:Nick Moir She said she "just stood there" when she realised William was gone. "I hear a roar [from William] and then I hear nothing. Mum and I are talking, and I still hear nothing and I think 'That's really weird.' I look across at Mum and say, 'It's just too quiet.' "He's gone."

After desperately searching the yard and street, she called triple zero, sparking a massive hunt from police, the RFS, neighbours and volunteers. Loading In his opening address, council assisting the coroner Gerard Craddock, SC, said it was not widely known that William's foster family were supposed to travel from Sydney to Kendall on the day he disappeared. However, a cancelled meeting allowed the family to make the four-hour trip north on September 11, a day ahead of schedule. While William's foster-father took a teleconference call from a nearby pharmacy, William, his sister, foster-mother and foster-grandmother enjoyed a relaxing morning at home, the inquest heard on Monday.

"The children were excited to see nanna," Mr Craddock said. Two years before his sudden disappearance made him a household name, the boy had come to the attention of police, the inquest was told. William Tyrrell's biological father, on the right, attends the inquest. Credit:Nick Moir In February 2012, Family and Community Services came to collect William after a court had ruled that he was to go into the care of the Minister for Family and Community Services. He wasn't there, leading police to issue a warrant for the arrest of his biological mother.

A month later, he was located at the home of a relative, then taken into foster care, the Coroner's Court at Lidcombe heard on Monday morning. Loading Replay Replay video Play video Play video "Police have not drawn the positive conclusion that a known relative or associate was not involved in William's disappearance," Mr Craddock said. Seventy-four per cent of children who are abducted and murdered by strangers are killed within three hours of being abducted, the court heard. But "William is not a statistic", Mr Craddock warned, and the court makes decisions based on evidence.