A mother in Nashville, Tenn. Is trying to figure out how her 7-year-old daughter was left on a school bus after it made its rounds and made its way back to the bus yard.

Police said the little girls fell asleep on the bus, which was dropping children off at the end of the school day, and the driver did not know she was still on the vehicle when he returned it to the bus yard.

"I just don't understand if my baby was on the second seat of a bus, how could he miss my baby," the girl's mother Satin Sharply told local television station WSMV.

The girl should have been dropped off at her home at around 5:30 p.m., Nashville Police said. When she did not come home, Sharply called 911.

The girl was found by neighbors who live in an apartment building across the street from the school. They heard her crying and lifted her over the fence, another local television station, News Channel 5 reported.

The school's principal said the bus driver was "overly comfortable" with his job and did not check the bus before leaving work. He has been fired from his job, the chairman of Smithson Craighead Academy told WSMV.