The accident happened just before 11:00 on the 1200 block of Roosevelt Drive, near Township Line Road.
According to officials on scene, the 10-year-old boy was riding his skateboard when he slipped and fell into the street and went right underneath a car.
Cuthbert was pronounced dead on scene.
The boy is said to have been in Upper Darby with his mother and sister visiting family.
The car in the fatal accident did stop. No charges have been filed.
