The section of the East River Drive from 23rd to 34th Streets was completed in October 1941. It was built on wartime rubble dumped by cargo ships returning from Bristol, England, during World War II. The German Luftwaffe bombed Bristol heavily. After delivering war supplies to the British, the ships' crews loaded rubble onto the ships for ballast, then sailed back to New York, where construction crews made use of it. The final part of the original boulevard, between 34th and 49th Streets, opened in May 1942. Future reconstruction designs from 1948 to 1966 converted the FDR Drive into the full parkway that is in use today.