The Centers for Disease Control and Prevention’s notification system it used to track potentially infected air travelers coming into the U.S. went offline in mid-February at the start of the novel coronavirus pandemic, The New York Times reports. When the incoming flow of passenger data stopped—albeit briefly—local health officials reportedly contacted the CDC to express concerns that infected passengers could slip away into the U.S., and they were told to “just let them go.” The agency told state officials at the time that it had temporarily shut the system down to “improve data quality.” According to the Times, even when the system was working, officials complained that the information it provided contained duplicative records, wrong phone numbers, and wildly incorrect travel information that made it impenetrable. “We got crappy data,” said Maryland’s deputy health secretary Fran Phillips. “We would call them up and people would say, ‘Well, I was in China, but that was three years ago.’”