According to the chart just below the COVID Case Map, 130 schools across the city are closed today. Have to assume this is due to outside testing done by or reported to Test and Trace. The chart was updated yesterday at 6 p.m. See column "Currently in Effect."
https://www.schools.nyc.gov/school-year-20-21/return-to-school-2020/health-and-safety/daily-covid-case-map?fbclid=IwAR1mBeeiIKG6OO-oPbTqRnBE7OmOKurOn1gY8m-NVhIys7fzHq9n_C_Ir68
Just got off the phone with PS52. They will resume classes Tuesday Jan 12