The Boston Police Department reports a 16-year-old student at the Henderson K-12 Inclusion School upper campus punched the principal to the ground as school let out Wednesday afternoon.

Principal Patricia Lampron, who is over 60, was unconscious when a police officer on standard school-release duty outside the upper campus, 18 Croftland Ave., got to her around 2:30 p.m. She was transported to a local hospital by ambulance with injuries considered serious but not life-threatening, police say.

The girl was arrested on charges of assault and battery on a person causing serious injury and assault and battery on a public employee, police say.

In a statement, Lampron's daughter, MaryKate, said Lampron "will need time and support" to recover from her injuries and the family expects "a full investigation into the circumstances of the attack to ensure the safety of all the students, staff and teachers in the Henderson School Community."

Remaining school administrators have ordered the school's upper campus shut tomorrow as they try to get to the bottom of what happened and so that teachers can meet to figure out how to help students who return when the campus re-opens on Friday, according to a copy of an email message sent to parents and posted by Start Smart BPS.

Members of a BPS crisis team will be at the upper campus on Friday as well to try to help students - and staff.

All students involved in this incident will be subject to consequences from law enforcement and discipline in accordance with BPS polices. We will conduct a thorough investigation into this incident which will inform our immediate response and the development of a longer-term plan to provide support and ensure the safety of the entire Henderson community.

The lower school will open as normal Thursday.