"I was looking around in the truck, driving through the subdivision ... you feel powerless; you just hope there's going to be a good outcome. It's an absolutely horrible feeling in the pit of your stomach."
Neighbours called police and within minutes more than 20 units arrived. Locals also joined the search, while alerts and news stories were circulated around social media.
An hour after Mila was first reported missing her scooter was found next to a creek more than 500m from her home - but there was still no sign of the preschooler.
"All these horrible thoughts go through your brain: 'She loves her scooter, why would she leave it? Why is it over there? Why has no one seen her between our house and there," Mr Rule told Fairfax.
The search continued with Mr Rule estimating more than 100 people scouring the streets.
Then, some two hours later, an upset Mila walked through the front door.
Her parents were overcome with relief. But where she was remained a mystery.
"It's an absolute mystery how she managed to walk from wherever she was, through the 20-odd police units and all those searching for her and just walk through the door," her father told Fairfax.
"She's a little bit cagey about it. Over the next few days we will try glean a bit of information from her to see where she was and what happened."