New York City’s public school district, the largest in the US, will halt in-person instruction starting Thursday, Mayor Bill de Blasio announced, citing soaring coronavirus infection rates there and across the country. … The move doubtless came as a relief to some teachers, many of whom have expressed fear of being placed at increased risk of exposure to the highly contagious respiratory virus. But it will cause hardship for working parents forced to make new childcare arrangements once more.