UPPER DARBY, Pa. (CBS) — A mother was arrested after accidentally dropping bags of fentanyl in the parking lot while she was taking her child to school, police say.

According to Upper Darby police, 29-year-old Dollinda Williams was dropping off her kindergartener at St. Bernadette of Lourdes School in Drexel Hill last Thursday when she dropped baggies containing fentanyl in the school’s parking lot.

Police say they found 29 bags of pure fentanyl, along with 12 empty bags, in the parking lot.

Williams has been charged with possession and reckless endangerment.