Norwich — Superintendent Kristen Stringfellow has warned that the city school district was on the brink of closing every day with staffing shortages at critical lows and available substitutes for positions at all levels barely able to fill the gaps.

Late Thursday night, the scales tipped, and Stringfellow was forced to cancel school Friday. That meant no Norwich buses to Norwich Free Academy, Norwich Regional Technical High School, the Integrated Day Charter School and local parochial schools, although those schools remained open.

Stringfellow sent letters to parents and staff shortly after 9:30 p.m. Thursday, listing 133 staff who had called in absent for Friday for all reasons and only 40 “healthy” staff available to cover for them. The absentees included 56 teachers, 33 paraprofessionals, six registered behavior technicians, five social workers, four assistant principals, three nurses, two school counselors, one principal, one psychologist and one board-certified behavior analyst.

By Friday morning, the numbers worsened, Stringfellow said, with another 10 to 20 total staff who would have been absent.

"It would not be safe for our students and staff to hold school tomorrow," Stringfellow wrote in the letter to parents late Thursday. "For the past two weeks, we have been using every resource at our disposal to cover the mass staff absences we have been experiencing. However, we do not have the personnel to cover this number of vacancies."

During a teleconference Friday morning with city leaders and public health agencies, Stringfellow said 154 students and staff members were absent because of COVID-19 infections and quarantines, and that number has been climbing over the past four days.

The sudden closure prompted confusion over the status of transportation to nonpublic city schools. Stringfellow said since Norwich Public Schools contracts with the First Student bus company for transportation to all schools in the city, when the public schools are closed, city school buses do not run to the other schools.

Norwich must make up the canceled day in June and will run buses for the makeup day. If Norwich ran buses to the nonpublic schools Friday, she said, the city district would in effect be paying twice for one day of school transportation.

NFA is in a modified midterm exam week this week, spokesman Michael O’Farrell said. He said teachers were given options for the traditional midterm assessments, due to the COVID-19 uncertainties all students and staff face. Some are requiring enhanced lab work or essays, for example, or exams that carry normal grade-weight, rather than higher grading score.

About a quarter of Norwich NFA students were absent Friday, O’Farrell said.

“Those who are here are taking them. Those who are not will make them up," he said of attendance and exams Friday. “We notified parents a couple weeks ago that this was a possibility with not just Norwich, but any one of our districts. And we will work with kids who have missed today to make up work that has been missed. Kids do have the ability to stay connected, but during exams it’s a little different. No one will be penalized for missing today.”

c.bessette@theday.com