A New Jersey elementary school teacher was out of the classroom recovering from a dental surgery when her students, under the supervision of a substitute teacher, decided to stage a mock slave auction.

The students organized the event themselves as they were studying their colonization unit and got to the part about the Triangular Slave Trade. They filmed their slave auction, and when the teacher returned to school and saw the video, she told parents what had happened in a letter, this according to a report by NJ.com.

“While I understand the creative effort, and the impact it had upon the students who viewed this, I used it as a teachable moment to elaborate on the gravity of this part of our history,” the teacher wrote. “I was concerned about the students who viewed and participated in this re-enactment and would like to convey this event to you so we can address the students’ perceptions as a whole.”

A spokeswoman for the district, Suzanne Turner, lauded the teacher’s response, saying, “The activity was not part of the curriculum, not part of the teacher’s assignment, not condoned by the teacher, not authorized by the district.”

“Upon hearing about the impromptu re-enactment and video while she was out, the teacher proactively reached out to parents to inform them not only of what had happened, but also how she was addressing this with students.”