Utah police said they got “quite a surprise” when they found a nine-year-old girl driving a car with her four-year-old sister in the passenger seat early on Wednesday morning.
The sisters told officers they were heading to California because they wanted to “swim in the ocean”.
They drove on two major roads, hit another car and then crashed head-on into a lorry, police said on Twitter. The sisters were both wearing their seatbelts and were not hurt.
Utah’s West Valley City Police Department said the girls woke up at about 3am on Wednesday, and took the Chevy Malibu while their parents were sleeping in their West Jordan home.
Their plan was to drive from the landlocked state to California – at least a 10 hour journey – for a beach holiday.
The nine-year-old drove the car for about 10 miles (16km) before she hit another vehicle, drove over a central reservation and crashed into the lorry, police said on Twitter.
The lorry driver, who was also not injured, had already called police after he saw their car hit the other vehicle.
Video from the body camera of one of the police officers at the scene shows the aftermath of the crash, and the damage to the red Chevy Malibu. One of the officers can be heard saying: “It’s crazy! She’s driving?”.
The sisters’ parents did not know they were missing until police woke them up and told them about the crash, Detective Scott List of West Jordan police said.
“The parents were horrified and very shocked to find their kids were gone,” he told local media.
There was a similar incident in Utah a year earlier, when a five-year-old boy took his family car to go and buy a Lamborghini, telling police he had left home because his mother refused to buy it for him.