A 6-year-old boy remained hospitalized Saturday after a school bus dragged him along the road for about 60 feet.

Shane Stout had skin scraped from his torso, patches of hair ripped off his head, a broken thumb and bruises on his face after Friday's accident on the Cattaraugus Indian Reservation, authorities said.

The doors of the bus closed on Shane's backpack and the driver took off without realizing the boy was stuck. The driver finally stopped after other children on the bus alerted him, authorities said.

Erie County Sheriff's deputies said a full investigation would take several days.

Stout is expected to be released from the hospital within the next few days.