Amazon deliveries have become a lifeline to millions of Americans as they bunker down in their homes to avoid the coronavirus pandemic. But the company confirmed its first positive COVID-19 case in a U.S. warehouse Wednesday, in a major threat to its ability to carry out operations. The Atlantic first reported that workers at an Amazon warehouse in Queens, New York, were sent a message reading: “We’re writing to let you know that a positive case of the coronavirus (COVID-19) was found at our facility today.” The development came as Amazon was already struggling to meet the rapidly increasing demand for home deliveries of food and other essentials. Meeting demand would become even more difficult if warehouse workers start being forced to take time off sick or have to self-quarantine. Amazon said it had temporarily closed the Queens delivery station for cleaning, and that staff had been sent home with full pay.