Lollapalooza, which also took place on Park District property and saw 100,000 people per day descend on Grant Park during the four-day festival in late July and early August, required attendees to show a negative COVID-19 test administered within 72 hours of entrance or proof of vaccination. The average daily number of new COVID-19 cases in Chicago has more than doubled in the weeks since the festival, and the city has since implemented an indoor mask mandate.
