In a May 2020 COVID-19 outbreak at a high school in Jerusalem, infection rates were higher among younger students (grades 7-9) compared to older students (grades 10-12). Rates peaked in the 9th grade (20 cases in one class, 13 in two others) and 7th grade (14 cases in one class). Among the 25 infected teachers, 7 were exposed to these four highly infected classes. Although 7th-9th graders had classes in a separate wing from 10th-12th graders, all students shared the schoolyard and public spaces.