CHICAGO: As the shrill sound of whistles echoed through a parking garage in Chicago’s North Side on Tuesday, two people flung their car doors open, ducked inside and shrank down into their seats. Outside, a convoy of federal immigration enforcement vehicles that had arrived in the area just minutes prior sped off. “We just saw a bunch of guys with whistles that chased them out,” said Luke, a landscaper who was working nearby and declined to share his full name.