When universities across the U.S. reopened and welcomed tens of thousands of students back to campus this fall, students partied in apartments, at pools and on the lawns of Greek houses — celebrating as if COVID-19 did not exist. Local public health departments and universities alike received thousands of reports about students at over-packed parties and bars where they could be seen maskless, violating social distancing and gathering size limits. Some schools created ways for complaints to be filed.

An analysis of the efforts at four major Midwestern universities shows that no matter what schools tried — whether it was Illinois’ much-touted testing program or Missouri’s lack of comprehensive or random testing — the results were much worse than predicted. At those campuses and the flagship universities in Indiana and Wisconsin, at least 15,000 tested positive for COVID-19 this fall.