Chicago Public Schools said schools will be closed a fourth day Monday as Mayor Lori Lightfoot and the Chicago Teachers Union traded barbs over the weekend. In a district-wide email sent Sunday, a spokesperson announced that classes had been canceled Monday, the fourth day in a row since the bitter feud was sparked last week by CTU’s vote against a return to in-person learning. Concerned by the recent surge in COVID-19 cases, the union presented a proposal Saturday suggesting remote classes be held until mid-next week. Lightfoot, in return, told union leaders “you’re not listening.” She demanded teachers make a physical return to the classroom, saying in a Sunday Meet the Press appearance that the union had staged “an illegal walkout” by voting against in-person learning last week. “They abandoned their posts and they abandoned kids and their families,” she seethed. With many members continuing to tweet under the hashtag #LoriLockout, CTU released a statement in response, saying, in part, “Educators are not the enemy Mayor Lightfoot wants them to be.” Despite the acrimony, the mayor said she remained “hopeful” about coming to an agreement, and a union official told members that CTU leaders remained at the bargaining table well into Sunday night, calling it “a good sign.”