Northern Virginia Community College’s Alexandria campus received the threat on Tuesday, prompting the campus to cease operations as the investigation is underway.

“Early this morning, the NOVA Police Department was notified of an anonymous bomb threat to the Alexandria Campus,” said NOVA Director of Communications Dawn Selak in a statement sent to Newsweek. “Out of an abundance of caution, the College decided to close the campus. Following an additional anonymous threat, NOVA has decided to close all campuses today.”

The school is currently working with federal, state and local law enforcement authorities in the ongoing investigation.

Biden, who teaches a class on the campus, was informed of the threat before she left the White House, according to her press secretary.

“The First Lady was informed about a bomb threat at Northern Virginia Community College prior to departing the White House for class this morning,” the secretary wrote in a statement. “At no point was she in any danger.”

Students have been advised to avoid the campus and to “follow instructions of authorities,” according to a notice posted on the school’s website.

Biden is listed on the NOVA website as a nine-month professor teaching at the Alexandria campus, earning an approximate salary of $86,000 according to her faculty contract. Newsweek previously reported that she is listed in the faculty catalog under her middle name Tracy, teaching a class called College Composition I that aims to “introduce students to critical thinking and the fundamentals of academic writing.”

In September, Jill Biden made history by returning to the classroom after her husband Joe Biden became president. She is the first U.S. first lady to hold a salaried position outside of the White House. “Teaching isn’t just what I do. It’s who I am,” Jill Biden told Good Housekeeping magazine at the time.

Biden’s decision to continue teaching was seen as a major step forward for educators, who expressed hope that her perspective would help make education a priority for the current presidential administration.

“She sees it up close and personally and now, in the position as first lady, not only does she give voice to that from a place of understanding, she has an opportunity to create a platform and to have influence,” Becky Pringle, the National Education Association president, told NPR at the time of Biden’s announcement.

Earlier this year, the first lady confirmed that funding to make attending community college tuition-free was no longer included in the stalled Build Back Better Bill.

“We knew that this wasn’t going to be easy. Joe always said that,” Biden said while attending the 2022 Community College National Legislative Summit. “Still, like you, I was disappointed because, like you, these aren’t just bills or budgets to me, to you, right? We know what they mean for real people, for our students. And it was a real lesson in human nature that some people just don’t get that.”

Update 3/29/22, 1:15 p.m. ET: This story has been updated to include a statement from Northern Virginia Community College.