A school bus driver was placed on administrative leave after a special needs student was found abandoned for about an hour in the back of a bus, the Apple Valley Unified School District said Monday.
The preschool student was discovered last Tuesday by another bus driver at the end of the route, the district said. The child was unharmed.
Just how the child was left behind was being investigated by the San Bernardino County Sheriff's Department, the district said.
"Words cannot express how dismayed we are that this occurred and how seriously we are taking this incident," the district said.
A refresher training course was held for employees the following day, in addition to other safety measures.
The incident comes less than two weeks after a 9-year-old girl riding a school bus in Oxnard was dropped off in an unfamiliar neighborhood, where she wandered for an hour and a half before neighbors came to her aid.
Legislation intended to prevent children from being left unattended on parked school buses is headed to Gov. Jerry Brown. The bill comes in response to the 2015 death of Paul Lee, a 19-year-old with autism. Lee was left for hours on a hot school bus.