The St. Louis Park Public Schools in suburban Minneapolis held in-person learning all semester, with no school closures for COVID-19 infections despite the spread of the delta variant.

But because of staff fatigue, and amid an oncoming wave of omicron-driven COVID-19 infections, the district finally has succumbed. It’s closed for a full two weeks ahead of the new semester starting Jan. 3. “The overall feeling is one of exhaustion,” Superintendent Astein Osei told the school board Nov. 23, ahead of an unusual mid-year vote to add two days to the holiday break.

Across the country, school districts and families are stumbling toward the finish line of a punishing semester. At some points, nearly all schools appeared back to normal with daily, in-person instruction. But disruptions abounded. COVID-19 exposures sent kids and staff home to quarantine. Teachers battled student misbehavior, from low-level defiance to more fights, threats and gun violence. Staffing shortages shot up. Parents waged their own arguments over race, public health and other issues.

And now, omicron. As the country braces for an onslaught of new infections driven by the more transmissible COVID-19 variant, schools and districts are shuttering and some are preparing to return to virtual instruction — the very mode of education this year was supposed to jettison.