SUN PRAIRIE, Wis. (AP) — Administrators at a Wisconsin middle school said Monday they have suspended teachers who were involved in an activity for sixth graders that included a question about how the students would punish slaves.

An email to parents at Patrick Marsh Middle School in Sun Prairie, about 15 miles (24.14 kilometers) from Madison, apologized for a “grave error in judgment” during the social studies class and said an unnamed number of teachers have been placed on administrative leave.

The lesson was meant to show the politics of ancient Mesopotamia and included one scenario that stated, ”A slave stands before you. This slave has disrespected his master by telling him ‘You are not my master’ How will you punish this slave?” It further explained that under Hammurabi’s Code the slave would be put to death.

Principal Rebecca Zahn and Associate Principal Amy Schernecker said the assignment was upsetting to parents and students. They said they will be following up with students about the event and offering services to those who need additional support.

Michael Johnson, president and CEO of the Boys & Girls Club of Dane County, said the assignment was “insensitive” and “totally inappropriate,” especially on the first day of Black History Month.