are back in the classroom. coming up, doctors on stand by to answer the questions you tha have tested positive for covid-19. of the 530, nearly 400 are students. the district's testing and contact tracing programs have yet to be fully implemented despite assurances to parents their children would be safe. nbc's marv barrett is live at a chicago elementary school where 11 of 17 classrooms, 11 of 17, currently in quarantine. and mar, there's a parent i know, a chicago public schoolteacher. she told you she's, quote, walking in the door with trauma every day. what else are you hearing there? and how are city officials handling all of this? >> reporter: well, nearly a