From Mesa, Arizona's KPHO News:
A teenage girl accidentally ran over and killed her 17-year-old brother as the two played around in an Arizona shopping mall parking lot. "Apparently some horseplay ensued where he jumped in front of the car and she stopped, he'd get out of the way and as she'd move, he'd jump back out," said Mesa Police spokesman Ed Wessing. The last time that happened the sister accidentally pressed on the accelerator, was unable to stop and ran over the brother, officers said.
Deep condolences to all involved, as losing someone to fatal horseplay can be a life-ruining mindfuck. One minute you're goofing around in a shopping mall parking lot on New Year's Day and the next minute you're that girl who killed her brother. (Unfortunately, I'm writing somewhat from experience, as fatal horseplay claimed the life of my fifth-grade best friend, who was unloading the dishwasher with his older brother when a kitchen knife inspired a Star Wars-themed light-saber battle, with the attendant horseplay adding up to a severed aorta. I wasn't there when it happened, but the event made me a lifelong anti-horseplay advocate.)