The event, known in the United States as the fall of Saigon and conjuring images of panicked Vietnamese trying to crowd onto helicopters to be evacuated, is celebrated as Reunification Day here in Hanoi. The holiday involves little explicit reflection on the country’s 15-year-plus conflict, in which North Vietnam and its supporters in the South fought to unify the country under communism, and the U.S. intervened on behalf of South Vietnam’s anti-communist government. More than 58,000 American soldiers died in the fighting between 1960 and 1975; the estimated number of Vietnamese soldiers and civilians killed on both sides varies widely, from 2.1 million to 3.8 million during the American intervention and in related conflicts before and after.