On the first day of school at Etowah High School in Georgia on Aug. 3, dozens of seniors packed together to pose side-by-side for a photo. Not a single smile was covered with a mask.

Now, just over a week later, the students all have been sent home and the school is shut.

In all, more than 900 students and staff in the Cherokee County School District have been ordered to quarantine as of Tuesday morning after 59 students and staff tested positive for covid-19, according to school officials. A third of those quarantined are from Etowah High School, which has had 14 confirmed cases.

Cherokee County School District Superintendent Brian V. Hightower said in a message to the community on Tuesday that the high school will be shut until Aug. 31 and that the number of people who need to quarantine could “increase dramatically” as more positive test results come in.

“This decision was not made lightly; it was made with the support of School Board Members, and was determined, as all of our quarantine decisions are made, in consideration with the Department of Public Health,” Hightower said.

The outbreak in Cherokee County is the most severe yet among schools that have already reopened, but it is far from the only district where the novel coronavirus has derailed in-person classes. In Livingston Parish, La., more than 140 students have been quarantined as of Tuesday after 17 employees and an unidentified number of students tested positive for covid-19. Officials at a middle school and high school in Muncie, Ind., said Tuesday they are shutting down for two weeks after sending more than 200 students home to self-isolate.

Other schools this week joined the ranks of those starting remotely. The school board in Roanoke voted Tuesday to start public schools online because the community is seeing rising cases, while Elizabeth School District in New Jersey said it would do the same after more than 400 teachers said they wouldn’t return to the classroom.

Cherokee County’s announcement came on Georgia’s deadliest day yet, with reported covid-19 fatalities. But as the virus keeps spreading in a state that has seen more than 220,000 cases and more than 4,300 fatalities, more than 80 Georgia districts still plan to start some form of in-person schooling by Monday, the Associated Press reported.

Cherokee County, which is about 30 miles north of Atlanta, welcomed 30,000 students back to 36 schools on Aug. 3. The school district gave families the option of remote learning, but 77 percent decided to attend school in person, Hightower said.

According to the district’s reopening plan, staff are required to wear masks but students are not — a fact that became clear as pictures from the first day of school circulated online. The district also required teachers to fill out self-screening and temperature checks, but the plan did not indicate whether students would also receive temperature checks before entering school.

School officials warned at the time that despite the precautions, an outbreak could quickly halt in-person classes.

“As we prepare to begin our new school year, I’d ask you to please continue to keep those words in mind: flexibility, patience, grace,” Hightower said in a message on July 9. “The virus doesn’t care about our plans, and we may find ourselves in situations where our plans must change, again with only one day’s notice.”

Hightower’s warning came to fruition just over a week after schools reopened. In his letter on Tuesday, he said the district had mandated a two-week quarantine for 925 students and staff. Nineteen schools in the district are affected by the quarantine, the AP reported.

Hightower also encouraged parents to instruct their children to wear masks, despite there not being a statewide mandate.

“We know all parents do not believe the scientific research that indicates masks are beneficial, but I believe it and see masks as an important measure to help us keep schools open,” Hightower said.

Going forward, Hightower encouraged families in Cherokee County to work together to keep the virus from further affecting the schools.

“We need our entire community to help us keep our promise — we need you to stay home when you’re sick; get tested if you’re symptomatic; report your child’s positive test to our school; follow the quarantine and limit interaction with nonfamily members during this period; social distance when you can and wear a mask when you can’t,” he said.