New U.S. coronavirus cases could more than double to 100,000 per day if the current surge spirals further out of control, the government's top infectious disease expert warned on June 30. "Clearly we are not in total control right now," Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, told a U.S. Senate committee. "I am very concerned because it could get very bad."