In her 17-year career, she has never once canceled a show because of illness. That track record is part of why the Eras Tour has been described as a once-in-a-generation phenomenon.

Swift admitted that the decision to cancel even one concert was “devastating,” but explained that she could not risk the health of her crew, her dancers, or the thousands of fans who would be gathering in the stadium.

How It Happened

According to insiders close to the tour, Swift began feeling unusually achy and fatigued following last night’s marathon three-hour performance. At first, she chalked it up to the physical toll of back-to-back shows.

But when she awoke the next morning still feeling drained, she took a rapid test that confirmed the diagnosis. By mid-morning, her management team had already begun rearranging schedules and alerting local officials in Chicago.

One source told Variety: “Every single band