By CAROLYN THOMPSON and KAREN MATTHEWS Associated Press
NEW YORK (AP) — A resurgence of the coronavirus in New York City is threatening to halt the nation’s biggest experiment with in-person learning. Mayor Bill de Blasio has said he will close school buildings if 3% of coronavirus tests over a seven-day period came back positive. The mayor says the city is preparing to close all school buildings as soon as Monday if the rate crosses the threshold over the weekend. It is currently 2.8%. Some parents are expressing frustration that they are being asked to decide about sending children back to school when the city itself is not even sure of next steps.