TiKiya Allen was riding her bicycle, the sun still in the sky, when she was struck in the back with a bullet and killed.

The 18-year-old nursing student, who had just finished her first year at Oakland University in Michigan, was on her way to a friend’s house in Detroit around 4:30 p.m. this past July 21 when gunfire sprayed from the open window of a car that had rolled up nearby. None of the bullets was meant to hit the teen, police believe. That fact has made it even harder for TiKiya’s mother Kai Cooks to grapple with the loss.

“It’s just not fair,” Cooks wails over and over. “I just want my baby back.”

Also this summer, a 7-year-old boy in Memphis was killed in a drive-by shooting moments after he had finished watching fireworks outside on the Fourth of July. Over the Labor Day weekend in Chicago, a 4-year-old boy was getting a haircut inside his home when two bullets pierced a window and struck him in the head, killing him, police say. Three other victims, as young as 11, were injured at a back-to-school event the same weekend when shots were fired into the crowd.