New York City's public school system, the country's largest, will delay the opening of classes by 11 days to Sept. 21 under an agreement with unions that pressed for stronger coronavirus safety measures, Mayor Bill de Blasio said. Subscribe: http://smarturl.it/reuterssubscribe Reuters brings you the latest business, finance and breaking news video from around the globe. Our reputation for accuracy and impartiality is unparalleled. Get the latest news on: http://reuters.com/ Follow Reuters on Facebook: https://www.facebook.com/Reuters Follow Reuters on Twitter: https://twitter.com/Reuters Follow Reuters on Instagram: https://www.instagram.com/reuters/?hl=en