BOSTON (CBS) – The Dr. William W. Henderson Inclusion School in Dorchester, Massachusetts is closed Thursday after a principal and another staff member were attacked by a student during dismissal Wednesday.

When Boston Police arrived, an officer found Upper Campus Principal Patricia Lampron unconscious on the ground being tended to by staff members. She was taken to a hospital for treatment of serious injuries which are considered to be non-life-threatening.

READ MORE: Steph Curry Closes In On 3-Pointers Record As Warriors Top Blazers

Henderson K-12 Inclusion School Principal Patricia Lampron. (Family Photo)

The principal’s daughter, MaryKate Lampron, released a statement Thursday on behalf of the family.

Today our mother, Patricia Lampron, was violently attacked at school and seriously injured by a student. She was taken to the hospital by ambulance where she is being assessed and treated for her injuries. Anyone who knows her knows how passionate she is about this school, it’s students and the Henderson School community. Our primary concern is her health and safety. She will need time and support to recover from her injuries. We expect a full investigation into the circumstances of the assault to assure the safety of all the students, staff and teachers in the Henderson School Community. She wants everyone to know that there is NO place for violence in our schools.

According to WBZ-TV I-Team sources, the 61-year-old principal suffered broken ribs and a head injury.

A 16-year-old girl was arrested and will be arraigned in Dorchester Juvenile Court on assault and battery charges.

READ MORE: Berkeley Police Arrest Convicted Sex Offender For Allegedly Accosting Teens, Claiming To Be Police Officer

Another staff member was allegedly hit as well, but it’s unclear what injuries were sustained.

The incident was witnessed by many students, staff and parents.

“This violent behavior will not be tolerated,” Superintendent Brenda Cassellius said in a statement. “The health, safety and well-being of our students and staff is our top priority at Boston Public Schools. I am personally involved and am ensuring we are taking immediate and swift action.”

Cassellius said the decision to cancel school Thursday was for the utmost caution.

“This incident is disturbing and completely unacceptable,” Cassellius said. “We want to be clear: Violence of any kind is not tolerated and will not be tolerated in the Boston Public Schools.”

Students in grades 2-to-12 attend the Upper Campus of the Henderson School.

MORE NEWS: 'This Is The Worst Time' – Half Moon Bay Merchants Blast PG&E Utility Work, Highway 92 Backups Before Holidays

The Boston Public Schools crisis team and other support staff will be available to students and teachers when they return to the classroom on Friday.