President Donald Trump has moved quickly to remake the Department of Homeland Security by firing the heads of the Transportation Security Administration and Coast Guard before their terms are up while eliminating all the members of a key aviation security advisory group.

Homeland Security officials have removed Adm. Linda Fagan from her role as the Coast Guard’s commandant, according to a note sent to service members — the first firing of a top military officer under the Trump administration.

The Trump administration ousted Coast Guard Commandant Linda Fagan, who is the first woman to lead a branch of the U.S. military.