NEW YORK — The head of New York City’s teachers union sounded the alarm on Monday about staffing issues due to sick calls reported across the public school system as COVID-19 cases skyrocket.

In Brooklyn, PS 58 pivoted to remote learning on Sunday night after a number of sick calls. The sudden shutdown is now under investigation because school leadership made the decision without permission from the Department of Education, according to a city spokesperson.

City leaders said the substitute teacher pool is ready to go. But United Federation of Teachers President Michael Mulgrew said he’s concerned about staffing.

“If people are sick, we do not want them coming to school. If they’re showing symptoms, we do not want them coming to school,” he said.

While Mulgrew called for a temporary shift to full remote learning until this wave of COVID-19 cases subsides, Mayor Eric Adams has vowed to keep classrooms open.

“We want to be extremely clear that the safest place for our children is in a school building and we are going to keep our schools open,” Adams said.

The one thing the teachers union and the mayor’s office can agree on right now is the need for a state-level school testing mandate so that all students can be swabbed at the city’s discretion. However, the governor and state Legislature need to make that call.

Meanwhile, new Schools Chancellor David Banks announced a new Department of Education COVID command center.

“Principals and district leaders can escalate any issues they need help with,  including ensuring buildings have staff to safely operate,” said Banks.