The liquid was brown-orange, and it burned on contact. On June 3, 1963, at the Bến Ngự Bridge near the Perfume River in Huế, South Vietnamese soldiers emptied the contents of tear gas grenades directly onto a crowd of 1,500 Buddhist demonstrators. The grenades were old French colonial stock, dating back to World War I, and their chemical agent had never properly vaporized. Instead of dispersing as gas, the liquid poured onto the skin and scalps of people kneeling in prayer. Sixty-seven were hospitalized with severe blistering and respiratory damage. The attack became a turning point in the Buddhist crisis that would consume South Vietnam for the rest of 1963 and ultimately lead to the overthrow and assassination of President Ngô Đình Diệm.
The trouble began with a flag. On May 7, 1963, government officials invoked a rarely enforced 1958 regulation, Decree Number 10, to prohibit the display of religious flags. The timing could not have been worse: Vesak, the birthday of Gautama Buddha, was days away. Buddhists across South Vietnam were preparing for their most sacred holiday, and the ban meant they could not fly the Buddhist flag. What made the decree sting was its selectivity. Just one week earlier, Catholics had freely displayed papal flags at celebrations honoring President Diệm's elder brother, Archbishop Ngô Đình Thục. On May 8, Buddhists in Huế took to the streets. The police and army responded with firearms and grenades, killing nine demonstrators. Diệm blamed the Viet Cong. The Buddhist crisis had begun.
By June 3, the protests had spread across South Vietnam. In Saigon, 500 Buddhist laypeople, mostly young, gathered before the Government Delegate's office as 300 troops looked on. In Huế, where Diệm had banned all demonstrations, some 1,500 protestors assembled at Bến Ngự Bridge, intending to march to the Từ Đàm Pagoda. When they tried to cross, the ARVN unleashed six waves of tear gas and attack dogs. Neither stopped the crowd. Then soldiers cracked open the grenades and poured the contents directly onto the demonstrators. The chemical agent, housed in glass containers, was designed to vaporize upon activation by acid. The acid had failed. What reached the protestors was raw liquid -- later identified as chloroacetone or ethyl bromoacetate from French World War I stocks. Forty people suffered second-degree burns. U.S. Army chemists in Maryland eventually confirmed the canisters' origins, and subsequent inquiries cleared the soldiers of using poison or mustard gas. But the distinction meant little to a world watching images of chemical burns on the bodies of people who had been praying.
The outcry forced Diệm to negotiate. He appointed three cabinet ministers to meet with Buddhist leaders, and by mid-June the talks produced a Joint Communiqué promising religious equality. But the promises went unfulfilled. On June 11, the monk Thích Quảng Đức set himself on fire at a busy Saigon intersection, an image that seared itself into global consciousness and made the crisis impossible to ignore. Through the summer, demonstrations and self-immolations continued. On August 21, Diệm's family ordered South Vietnam's Special Forces to raid Buddhist pagodas across the country. The United States condemned the raids and began cutting aid to programs identified with the ruling Ngô family. Washington's message was received clearly by South Vietnam's generals.
Confident that America would not intervene to save Diệm, the South Vietnamese military staged a coup on November 1, 1963. The next day, Diệm and his brother Ngô Đình Nhu were captured and assassinated. What followed was not stability but a cascade of military juntas deposing one another, each government weaker than the last. The political chaos emboldened the Viet Cong, who made substantial gains against the South Vietnamese army. By 1965, the deterioration was so severe that the United States began deploying hundreds of thousands of combat troops, transforming an advisory mission into a full-scale war. The chemical attack at Bến Ngự Bridge had been a small incident in scale -- 67 hospitalizations, no deaths. But the image of soldiers pouring caustic liquid onto praying civilians crystallized something larger: a government at war with its own people. The crisis that followed reshaped not just South Vietnam but America's role in Southeast Asia for a generation.
Coordinates: 16.469°N, 107.578°E, along the Perfume River in central Huế. The Bến Ngự Bridge area is visible along the river's southern bank. Best viewed at 2,000-3,000 feet AGL. The Citadel of Huế and Từ Đàm Pagoda are nearby landmarks. Nearest airport: Phu Bai International Airport (VVPB), approximately 14 km southeast. Huế sits in a coastal lowland corridor between the Annamite Range and the South China Sea.