WALLED LAKE, Mich. — School bus surveillance video shows one student with special needs attacking a student with autism twice, WDIV reports.

Video shows a bus aide removing a student’s restraints at his stop and then that student attacking Cal McFarland, who is nonverbal, according to the news source. McFarland’s mother told WDIV that she and her husband were told that Cal hit his head on the window. However, Cal’s injury, a scar across his cheek, came from an attack from the same student minutes before. Cal yelled for help, but no one came to his aid, WDIV reports.

Cal’s mother told the news source that the bus aide and bus driver did not mention the attacks, and that they eventually found out what happened after meeting with school leaders and the school bus company. The school district and school bus company told WDIV that they are investigating the incident.

To read the full story and view the video footage, go here.