With Armed Forces Radio broadcasting Bing Crosby's 'White Christmas' as a covert signal, American forces launched Operation Frequent Wind, evacuating over 7,000 Americans and South Vietnamese from Saigon by helicopter as the city fell to North Vietnamese troops. Desperate crowds stormed the U.S. Embassy compound. Helicopters were dumped overboard from carriers to make room for more flights, one of the war's most searing final images.
By late April 1975, North Vietnamese tanks were less than 20 miles from Saigon, and the South Vietnamese government's collapse was imminent. The prearranged signal to begin the final evacuation—the radio announcement of 105 degrees and rising, followed by the Bing Crosby song—set off a chaotic scramble across the capital.
Over about 18 hours, Marine and Air Force helicopters flew continuous sorties from rooftops and the U.S. Embassy compound to Navy ships waiting offshore, evacuating roughly 1,000 Americans and 6,000 Vietnamese allies, though tens of thousands of others desperate to flee were left behind. Crowds scaled the embassy walls; some clung to helicopter skids. Navy crews aboard the USS Blue Ridge and other vessels pushed dozens of South Vietnamese helicopters into the sea to clear deck space for incoming flights, since the pilots had nowhere else to land.
The operation ended just before Saigon fell on April 30, closing America's direct military involvement in a war that had killed roughly 58,000 U.S. service members and millions of Vietnamese. The photograph of a CIA employee helping people up a ladder to a helicopter atop a Saigon building became one of the era's defining images, even though it was widely misidentified as the U.S. Embassy itself.