MISSOURI CITY, Texas -

A school mix-up had a first grader at Palmer Elementary School in Fort Bend ISD wandering around his school for nearly an hour.

"The first two nights he went to sleep, crying that it was his fault," said the boy's mother, who asked Local 2 not to use her name.

The mother says her son was supposed to stay after hours for a tutoring session, but the teacher forgot and her son was left wandering alone for 45 minutes.

The child's mother was on her way to the school to pick him up when she saw her son walking by himself on the sidewalk along Highway 6, several blocks from the campus.

"I had to turn my head three times. I couldn't believe it. By the third time, I was in shock. I felt like I was going to have a heart attack," the boy's mother said.

The school district says it immediately launched an investigation.

District spokesperson Nancy Porter told Local 2 "We are reviewing all protocols in regard to students who are scheduled to remain on campus after school for tutoring and other education related services and steps have been put in place to ensure proper student dismissals."

The boy's mother says her son has delayed speech and while he hasn't been able to fully explain what happened, she says it breaks her heart that he blames himself.

"They are not explaining anything else to me. There are going to be a lot of questions we will never have answered," the boy’s mother said.