A Washington, D.C. elementary school has apologized to the students’ parents after the fifth graders were asked to portray slaves during a history lesson.

According to The Grio via a report from CNN, the incident took place at Lafayette Elementary School during a lesson about the Civil War and Reconstruction. One of the students were asked to drink from a segregated water fountain.

In a Dec. 23 letter issued to the parents, the school’s principal Carrie Broquard admitted, “students should not have been tasked with acting out or portraying different perspectives of enslavement and war.”

The principal said that the students started the lesson by reading an article titled “A Nation Divided,” and while doing an accompanying group assignment some of the Black students were asked by their peers “to play roles that are inappropriate and harmful,” the letter said.

In a separate letter, Broquard called the assignment a mistake and said that it won’t be taught to other classes going forward. “At Lafayette, we believe in the importance of teaching painful history with sensitivity and social awareness. Unfortunately we fell short of those values in a recent 5th grade lesson,” she said. “We deeply regret that we did not foresee this as a potential challenge in role playing so we could set appropriate parameters to protect students.”

Members of the school’s staff are now required to participate in equality and race training. The school also has plans to establish a diversity and inclusion committee.

Broquard said the students who were asked to portray slaves are being counseled by the school’s social emotional support team to “process and talk through” the incident.

The principal added, “As the leader of the Lafayette school community, I am distressed this happened and saddened our students were hurt. The voices of our students, their resilience and their compassion continue to inspire me to lead us all forward in a better way.”