The massacre took place in the early hours of 22 August 1972 in the Almirante Marcos A. Zar Airport, an Argentine Navy airbase located near the city of Trelew, Chubut in Patagonia.

These two leaders, along with Fernando Vaca Narvaja, Roberto Quieto, Enrique Gorriarán Merlo and Domingo Menna, made up the so-called Leakage Committee, and were the only ones able to escape, thanks to a waiting Ford Falcon, and reach Trelew airport where an Austral BAC One-Eleven airliner, previously hijacked by a guerrilla group of supporters disguised as passengers, waited to fly the escapees to neighboring Chile, then ruled by socialist President Salvador Allende.

Seeing their chance of escaping disappear, the group called a press conference and surrendered without resistance to the Navy military personnel that surrounded the area, hoping the presence of journalists and judicial authorities would pressure the government to guarantee their lives.

The spectacular escape attempt and partial success of the six top guerrilla leaders, who later managed to travel from Chile to Cuba, had the military government of the self-proclaimed Argentine Revolution and the public in suspense for tense days.

While the government of Alejandro Agustin Lanusse tried to push the Chilean president Salvador Allende into deporting the political escapees as criminals, the whole area of Rawson and Trelew were virtually occupied by Army and Gendarmerie personnel, who were patrolling continuously and made additional escape attempts impossible.

Those killed were: Survivors: On 30 April 1973, rear admiral Hermes Quijada, who headed the press conference which circulated the military version of an alleged second escape attempt, was gunned down in Buenos Aires by ERP-22 de Agosto guerrillas.

[6] Two days later, Montoneros guerrillas set off an underwater demolition charge in the engine room of the Argentinian destroyer Santísima Trinidad, causing extensive damage but no casualties.