In June 1948, Joseph Stalin stopped all road and rail traffic coming into and out of the Allied sector of Berlin. He simultaneously cut off all electricity to the city, leaving only a 20-mile-wide sector of air corridors and one wayto get supplies to desperate, starving people. The United States, using the only method it could, led Allies in mobilizing an unprecedented airlift of thousands of tons of supplies each day. By September 1948, the airlift was transporting food, coal, medical supplies, and other necessities into West Berlin as aid for the residents. At the same time, the Russian military threatened to strike down any aircraft caught flying outside of the corridor. Finally, by April of 1949, Russia announced their intent to end the blockade, and in August of the same year, the United States airlift operation was terminated.