LOWELL, Mass. -- A Massachusetts school bus driver has been fired after leaving a 5-year-old boy alone on a bus for about five hours.

School officials and police in Lowell says the kindergartner did not get off the bus when the driver dropped off students on Wednesday morning and the driver failed to follow protocol by checking to make sure all students had disembarked.

The driver took the bus home and discovered the child when he returned to the bus to start his afternoon route.

School superintendent Salah Khelfaoui says the boy was thirsty but otherwise unharmed on a day when temperatures rose into the 80s. His parents took him to a doctor as a precaution.

The school district's bus service is contracted to an outside company. The driver's name was not disclosed.