PANAMA CITY, FL - An outraged mother in Florida is calling for action against her child's teacher for her comments on an assignment.

To mark a failing grade, the teacher wrote "WTF is this?" on the paper. The school's principal says he spoke with teacher, who admitted it was a mistake and apologized.

The school district and human resources are investigating the incident.

The principal is assuring the community the school will strive to do better.