At the height of the Cold War, the United States and the Soviet Union both possessed the capability of launching nuclear weapons. To prepare Americans for the possibility of nuclear war, agencies of the federal government implemented civil defense programs. These programs included the building of public and family civil defense shelters, stockpiling necessities, and the production of public service films to educate adults and children alike. One such film featured Burt the turtle, who instructed schoolchildren to "Duck and Cover" when the civil defense sirens sounded. The federal government also implemented plans for the continuity of government in the event of a nuclear attack. These plans included the relocation of the President and Congress to secret sites; plans that were practiced in simulated exercises called Operation Alert.