(AP) — Students in the nation’s third-largest school district will resume classes this week after leaders of the Chicago Teachers Union accepted a proposal with the district over COVID-19 safety protocols. Both sides had been locked in an increasingly bitter standoff that canceled classes for five days in the nation’s third-largest district. The full deal still requires approval by the union’s full 25,000 members, but students are expected back in class Wednesday with teachers returning a day earlier. Issues on the table have been metrics to close schools and expanded COVID-19 testing. The union voted last week to revert to online instruction and told teachers not to show up in person at schools as negotiations continued amid a surge in COVID-19 infections.