An elementary school in Northern Virginia is apologizing for trivializing slavery after students played a game in a physical education class that required them to simulate moving through the Underground Railroad.

As part of recognizing Black History Month, students in the third, fourth and fifth grades at Madison’s Trust Elementary in Brambleton, Va., were given a lecture this month about the Underground Railroad. The students were then divided into groups of six and were responsible for overcoming a physical obstacle, such as moving through plastic hoops without knocking them over, said Wayde Byard, Loudoun County Public Schools spokesman.

“It trivializes something that is important,” Byard said. “There was an error made here. . . . Slavery is not a game.”

The game, first reported by the Loudoun Times-Mirror, was supposed to teach teamwork, communication and cooperation, according to the school system.