The director of the Centers for Disease Control and Prevention and several top officials are departing in a massive shakeup at the embattled agency.

Susan Monarez, the CDC director, was fired just shy of a month into her role. At least four other officials have also submitted their resignations.

“Susan Monarez is no longer serving as the director of the Centers for Disease Control and Prevention,” stated a post on the Department of Health and Human Services’ X account. “We express our gratitude for her committed service to the citizens of America.”

The post further mentioned that Secretary Kennedy remains fully confident in the CDC, “which will continue to diligently protect Americans from infectious diseases both domestically and internationally.”

The Washington Post first reported on her ousting.

As per letters reviewed by NBC News, four other senior officials at the CDC have also tendered their resignations: Dr. Debra Houry, the CDC’s chief medical officer; Dr. Demetre Daskalakis, head of the National Center for Immunization and Respiratory Diseases; Dr. Daniel Jernigan, head of the National Center for Emerging and Zoonotic Infectious Diseases; and Dr. Jen Layden, director of the Office of Public Health Data, Surveillance and Technology.

The departures comes at a tumultuous time for the agency.

On August 8th, a shooter damaged windows in six buildings on the CDC campus, and a police officer was killed in the event. In the aftermath, Monarez aimed to reassure staff during a virtual meeting.

“We acknowledge that misinformation can pose significant risks,” Monarez remarked in the meeting, as per a transcript obtained by NBC News. “This impacts not just health, but also the trust of those we serve and those we aspire to earn trust from. Together, we need to restore that trust.”

Monarez had canceled a meeting with CDC staff, planned for the following Monday, last Friday. The meeting was to address safety issues and security improvements in light of the recent shooting incident.

“Unfortunately, we need to postpone Monday’s event for an HHS meeting that I have been asked to attend in person in DC,” Monarez wrote in an email to CDC staff seen by NBC News.

With Monarez’s firing, the agency returns to the leaderless state it has been in for the majority of the new Trump administration. Trump’s original pick for CDC director, Dr. David Weldon, was pulled from consideration hours before his confirmation hearing in March. Weldon, a former congressman from Florida, had a history of questioning vaccine safety.

Monarez briefly served as the agency’s acting director before she was nominated in Weldon’s place.