Chicago officials canceled classes citywide on Monday as they failed to reach a new agreement with the Chicago Teachers Union (CTU). Union members voted last week to abruptly shift to virtual teaching, a move rejected by Chicago Public Schools (CPS) and Mayor Lori Lightfoot. City officials instead canceled classes and have been seeking to convince teachers to get back in classrooms. So far, they have not been successful, leading to the fourth day of canceled classes. “Although we have been negotiating hard throughout the day, there has not been sufficient progress for us to predict a return to class tomorrow,” Pedro Martinez, the CPS CEO, told parents in a letter late Sunday. “We appreciate your patience and will continue providing you with updates as soon as they become available,” he added later. Martinez and Lightfoot, a Democrat, say the union’s actions amount to an illegal work stoppage because they cannot …