The correct answer is: "Planes dropped tons of supplies around the city each day."
The Berlin Blockade was one of the tense crisis that took place during the Cold War era. West Berlin, dominated jointly by the Western powers (US, UK and France) was embodied inside the German Democratic Republic, which was a communist republic under the influence of the URSS. In 1949, the soviets blocked the entry routes to West Berlin (railway, road, and canal accesses) so that supplies could not arrive to this area of the city.
The Western powers organized the denominated Berlin airlift, and the supplies arrived in West Berlin by plane.