In a futile effort to topple Argentine President Juan Perón, rogue aircraft pilots of the Argentine Navy drop several bombs upon an unarmed crowd demonstrating in favor of Perón in Buenos Aires, killing 364 and injuring at least 800. At the same time on the ground, some soldiers attempt to stage a coup but are suppressed by loyal forces.

Juan Domingo Perón was an Argentine military officer and statesman who served as the 29th president of Argentina from 1946 to his overthrow in 1955 and again as the 40th president from 1973 to his death in 1974. He is the only Argentine president elected three times and holds the highest percentage of votes in clean elections with universal suffrage. Perón is arguably the most important and controversial Argentine politician of the 20th century and his influence extends to the present day. Perón's ideas, policies and movement are known as Peronism, which continues to be one of the major forces in Argentine politics.

The Argentine Navy is the navy of Argentina. It is one of the three branches of the Armed Forces of the Argentine Republic, together with the Army and the Air Force.

On 16 June 1955, 30 aircraft from the Argentine Navy and Air Force bombed and strafed Plaza de Mayo, the main square of the Argentine capital Buenos Aires. The attack targeted the adjacent Casa Rosada, the seat of government, while a large crowd demonstrated in support of the president, Juan Perón. The strike took place during a day of official public demonstrations to condemn the burning of a national flag allegedly carried out by detractors of Perón during the recent Corpus Christi procession. The military reacted as a result of growing tension between Perón and his actions against the Roman Catholic Church. The action was to be the first step in an eventually aborted coup d'état. The number of identified bodies was put at 308, including six children, making it the deadliest terrorist attack in Argentine history. Some victims could not be identified.

Buenos Aires, controlled by the government of the Autonomous City of Buenos Aires, is the capital and largest city of Argentina. It is located on the southwest of the Río de la Plata. Buenos Aires is classified as an Alpha− global city, according to the GaWC 2024 ranking. The city proper has a population of 3.1 million and its urban area 16.7 million, making it the twentieth largest metropolitan area in the world.