A year and a half into the coronavirus pandemic, people are still discovering that it’s a not a good idea to pack hundreds of people indoors without asking them to wear masks or checking their vaccine statuses. A new report from the Centers for Disease Control and Prevention has linked 180 confirmed and probable COVID-19 cases to an Illinois church camp and conference held in mid-June. The camp—identified as the Crossing Camp in Rushville by the Chicago Tribune—didn’t mandate masks or vaccines, and the CDC reported that campers slept in groups of about 100 in “large, shared boarding facilities.” The CDC found 87 primary cases linked to the camp, 35 linked to a nearby men’s conference sponsored by the same church, and 58 secondary cases among close contacts. The CDC said 1,127 people from at least four states were exposed to the virus because of the camp, which has not commented on the CDC’s findings.