An 8-year-old boy’s decision to take his 6-year-old sister on a joyride ended in tragedy in Phoenix, when he crashed the car and killed his sister.

The children’s mother had bathed them and put them to bed Wednesday night, but couldn’t find them a half-hour later, according to media reports.

The frantic mother called police and reported the children missing and possibly kidnapped. She then went door-to-door searching for her pajama-clad kids, according to a report in yahoo!news.com.

The boy drove the car a short distance from home, hit a pole and crashed the 2010 Hyundai Elantra nearby, according to police.

The girl died of her injuries early Thursday morning, police said. The boy received minor injuries.

Read more about the story on abcnews.go.com.