A cluster of coronavirus cases has emerged at a Georgia high school that drew national attention last week after students posted pictures and videos of their peers walking without masks in tightly packed hallways, according to a letter sent to parents over the weekend.

Six students and three staff members at North Paulding High School have reported testing positive for the virus, Principal Gabe Carmona wrote in the letter, which was first reported by the Atlanta Journal-Constitution. He said the infected people were in school “for at least some time” last week.

Superintendent Brian Otott later announced that the school will close Monday and Tuesday and revert to virtual learning while the building is cleaned.

The district will announce Tuesday evening whether in-person instruction will resume the next day, Otott wrote to parents Sunday in a second letter, shared by a WSB-TV reporter.

Otott added that anyone who has tested positive, as well as close contacts of people who have the virus, must quarantine for 14 days before returning to school.

“I apologize for any inconvenience this schedule change may cause, but hopefully we all can agree that the health and safety of our students and staff takes precedence over any other considerations at this time,” Otott wrote.

The infections validate concerns in Georgia and nationwide that crowded conditions in the nation’s K-12 schools could facilitate virus transmission as the new academic year begins. Young people develop severe infections at far lower rates than adults, but experts warn that they could be vectors for infecting more vulnerable populations, such as older relatives in the same household.

Coronavirus cases among U.S. children rose sharply in the second half of July, with more than 97,000 infections nationwide, according to newly released data from the American Academy of Pediatrics and the Children’s Hospital Association.

Carmona, the principal, said custodial workers were cleaning and disinfecting the school building daily — a practice that offers only marginal protections against the virus, which primarily spreads through person-to-person contact, not from contaminated surfaces.

“The health and well-being of our staff and students remains our highest priority," Carmona said, “and we are continuing to adjust and improve our protocols for in-person instruction to make our school the safest possible learning environment.”

A representative for the Paulding County School District did not immediately respond to a request for comment Sunday.

The school of more than 2,000 in Dallas, Ga., was thrown into the national spotlight last week when students posted images on social media showing seas of students milling through the halls between classes.

The school district suspended two students who shared the images, prompting another wave of negative attention from critics who said administrators were silencing them. Administrators reversed the suspensions on Friday following the backlash.

Lynne Watters, the mother of one of the students, said her daughter would be able to return to school Monday with her disciplinary record unblemished. “The principal just said that they were very sorry for any negative attention that this has brought upon her," Watters said in a text message, “and that in the future they would like for her to come to the administration with any safety concerns she has.”

Officials have continually sought to play down concerns generated by images of the crowded corridors.

On Wednesday, Otott told parents in a letter that although the photo “does not look good,” the conditions were permissible under the Georgia Department of Education’s health recommendations.

The superintendent also misleadingly cited a state health department document listing the different ways people can become infected with the coronavirus. He claimed that exposure occurs after “being within 6 feet of a sick person with COVID-19 for about 15 minutes” but omitted other factors such as being coughed on that can cause the virus to spread faster and more directly.

Marisa Iati and Lateshia Beachum contributed to this report.

Read more: