Ubiquitous

In just days, the United States of America is shut down; the streets are empty in every town, and the birds singing are the only sounds heard. What is killing Americans by the hundreds, by the thousands, by the millions? Could it be the food they are eating, the air that they are breathing, or the lives they are leading? Could it be beautiful flowers that are killing them in hours? The head of the CDC in Atlanta is frantic; they are testing everything the United States citizens are using from the Pacific to the Atlantic! Could you be one of the millions?