DENISON, Texas (KTEN) — A Denison elementary student was left on her school bus for several hours on Wednesday morning.

The Denison Independent School District said the four-year-old fell asleep on the bus. She was not found until Lamar Elementary called the student's mother, Leslie Waldrop, to alert her that her daughter never arrived.

Waldrop put out a Facebook post expressing her disappointment in the school district.

Denison ISD spokesperson Brian Eaves, issued a statement saying, in part:

"We are thankful that following the incident, the student was safely returned to campus. DISD is committed to ensuring our students are safe. We will continue to evaluate the district's safety and security protocols, including those specific to the transportation department."