Mass layoffs are expected to start Tuesday night at the Department of Education, two sources told ABC News.

They said that the “reduction in force” notices are expected to go out at 6 p.m.

Nearly half of the department is expected to be eliminated, the sources said.

The announcement came shortly after DOE employees were told that their offices — including those in the National Capital Region, along with regional locations — would be closed for the day on Wednesday.

Citing “security reasons,” an email went out saying that the buildings would be inaccessible starting at 6 p.m., a source within the department told ABC News.

“You must vacate the building by that time,” a department email to employees reads in part, adding “All ED offices in the NCR and the regions will be closed to employees and contractor employees on Wednesday, March 12th.”

The email also instructed employees to take their laptops home with them after work on Tuesday.

“Please take your laptop with you when you depart on Tuesday. Employees will not be permitted in any ED facility on Wednesday March 12th for any reason.  All offices will reopen on Thursday, March 13th, at which time in-person presence will resume,” the email said.

The email also said that employees with approved telework agreements may work from home; however, such telework agreements are largely no longer in place, an employee told ABC News. The DOE called for its total workforce to return to its offices late last month.

The closure notification comes as President Donald Trump weighs an executive order to shutter the agency. The decision to sign that order was delayed due to concerns over questions the administration might get about vital programs that could potentially be gutted by it.

Inside the department, employees are bracing for uncertain futures.

“People are petrified to do their jobs,” an Education Department employee told ABC News recently. “People are worried about like, if I push back on something that somebody wants to do, right, and I say, that’s not really what the law says or is legal, am I going to get a bad performance and now they use a bad performance to kick me out?”

“Everyone here is holding their breath,” the DOE employee added.