Chicago Mayor Lori Lightfoot on Monday pointed to young adults in four specific neighborhoods as driving the city's "troubling" increase in coronavirus cases. At a news conference announcing a new vaccination site for union members in the city, Lightfoot noted that although Chicago is progressing in its vaccine distribution, "we are not out of the woods yet by a long shot." "Right now we are seeing a troubling uptick in our case positivity and daily case rates," Lightfoot said. "Folks, I just want to tell you, it was about three weeks ago that we were still on a downward trend...