Virginia Gov. Ralph Northam (D) said Monday that he is closing the state’s K-12 schools for the remainder of the academic year, prompting school officials across the state to scramble to reassure families that districts can develop a plan to keep students on track.

At a news conference, Northam described the closures as a “necessary” step in the state’s fight against the novel coronavirus, while acknowledging that the move will upend life for hundreds of thousands of families with children in public and private schools. He said that with help from the state, local school leaders will be able to decide how students can learn the material they were supposed to cover by the end of the year.

Virginia officials are working to obtain a federal waiver for standardized testing requirements, Northam said, and to ensure that students who were supposed to graduate in 2020 still can.

“By tomorrow, the state Department of Education will issue guidance to help school divisions think through those decisions to ensure that every student is served equitably,” Northam said. “I know this raises a lot of questions for parents and also for our students.”

His announcement prompted a flurry of messages and social media posts from school districts throughout the state, as officials rushed to tell families that they were dropping everything to plan for a future that seemed unthinkable just weeks ago. Virginia is the second state to shutter its school campuses for the rest of the school year, joining Kansas.

The decision raises thorny questions for nearly every aspect of life, including how to keep feeding families who rely on federally subsidized school meal programs, how to teach students who lack the resources or Internet access to learn at home, and how to reach children with disabilities, whose conditions may make it impossible for them to learn online.

But one looming crisis supersedes all others, Northam said Monday: the plight of essential workers such as doctors, nurses and grocery-store clerks, whose children suddenly have nowhere to go during school hours, at the very moment their parents’ professional skills are most needed. Virginia has 1.2 million children under the age of 12, Northam said, and about 80,000 of them are estimated to be the children of health-care workers.

Virginia will need to fill that void, Northam said, potentially by providing emergency child-care services staffed by a combination of employees from public schools and private day-care centers. He said the departments of social services and education would issue guidance on the matter soon.

“We must rally together,” Northam said.

The governor’s come-together call, accompanied by few concrete details, was a tactic adopted by Virginia educators throughout the day Monday. Most school officials announced they would continue virtual learning programs they had already developed to cover the next few weeks, planning undertaken in response to Northam’s order on March 13 — just 10 days ago ­— that the state’s schools remain shuttered for two weeks.

Per previous advice from the Virginia Education Department, none of that instruction is required or graded, and none of it covers new material.

But what comes after mid-April, when most programs will run out of material?

“We all have questions,” Arlington Public Schools interim superintendent Cintia Z. Johnson wrote in an email to families on Monday. “It is unfortunate it has come to this.”

Scott Brabrand, the superintendent of Fairfax County Public Schools, which serves 188,000 students, wrote to families within minutes of Northam’s announcement, saying that the school board would hold an emergency session Monday afternoon.

In the interim, Brabrand wrote, all he could say with certainty was that extracurricular activities and athletic programs are canceled for the rest of the year.

“We are navigating uncharted waters,” Brabrand wrote. “I know that we will persevere through this difficult time together.”

In Alexandria, Superintendent Gregory Hutchings Jr. said in an interview that his team had suspected something like this was coming for weeks and had begun planning how to respond.

Like other Virginia school systems, Alexandria City Public Schools — which serves 16,000 students — should be set through mid-April, Hutchings said. Until then, students will continue filling out instructional packets, delivered on the last day of school, that review previous material and ask them to complete activities such as dancing to classical music while learning about famous composers.

As children page through packets, staffers will be working to design and debut a virtual educational program that can last students for the rest of the school year. That program will have to teach new concepts — and somehow guarantee that lack of access to technology is not a barrier to learning.

Teachers throughout the system will put in at least five hours of work a week on the project, Hutchings said, and central office staff will be working “basically 24/7.” Though the task is daunting, he said, he is trying to see it as an opportunity.

“We can rethink how we teach kids,” Hutchings said. “It really has pushed us into this whole technology world — just this past week, I learned how to Zoom.”

As administrators huddled on Monday to sketch a path forward, teachers, parents and students gathered in their homes, struggling to reorient themselves to a new reality.

When Jennifer Colman heard schools were closing through the rest of 2020, her first thought was for her daughter. She wanted to know what questions were troubling the 15-year-old, a sophomore who attends public school in Fairfax County.

Colman had a guess: “What happens to varsity lacrosse? What happens to applying to college?” She readied herself to sit down and listen, she said.

“Then I’m going to start answering every single one of her questions,” Colman said. “I’m going to email officials, both elected and school board, I’m going to talk to neighbors, I’m going to do everything I can.”

Even before Northam started speaking, Fairfax County Public Schools English teacher Mary Kay Downes had laid out the ingredients for the most “comforting” dinner she knows how to make: potato leek soup. Downes, a veteran teacher, suspected something bad was coming.

Afterward, she fought to stay upbeat.

“I’m just not going to think this is the end of the world as we know it,” Downes said, stirring the soup. “I’m an optimistic person.”

A text from one of her students helped, she said. The student wrote Downes late Monday afternoon to tell her thanks — thanks for teaching her class the meaning of “resilience.”

“Which I do think,” Downes said, “they are going to need.”

Laura Vozzella contributed to this report.