ST. PAUL, Minn. - St. Paul Police are investigating after a 3-year-old boy was fatally struck by a car driven by his mother on Saturday.

When officers arrived at the parking lot on the east side of Harding Senior High School, they found a 39-year-old woman they say was "visibly shaken and emotional."

Police learned on the scene that the woman had been practicing driving in the parking lot with family members, when she accidentally pushed the accelerator instead of the brake. Police say she lost control of the car, hitting her 3-year-old son and pinning him against a large clothing collection box.

A passerby heard the crash and stopped to help, bringing the child and a family member to the hospital.

Police say efforts to save the boy's life were unsuccessful.

The mother and witnesses are cooperating with the investigation, and police say that there are no signs of alcohol or impairment playing a role. The investigation is ongoing.