Health experts warn U.S. cities of 'trouble ahead'

White House health experts on Thursday warned of a slow rise in the percentage of people testing positive for the coronavirus in a number of major U.S. cities and urged local leaders to remain vigilant to avoid a surge. Infectious diseases expert Dr. Anthony Fauci told CNN the increase is " a predictor of trouble ahead."Cities of concern include Boston, Chicago, Detroit and Washington. Even if most people are cautious, Fauci warned, those not wearing masks or following social distancing guidelin