A fourth-grade boy brought a small amount of leafy marijuana on Monday to Monfort Elementary School in Greeley, Colo., and sold it to three classmates on the school playground. He made $11 on the deal, John Gates, director of safety and security for Greeley-Evans School District, told ABC News.

The next day, one of the buyers brought an edible to school and gave it to the boy who sold him the weed.

One student admitted to taking a small bite of the edible but a medical exam did not indicate any harm.