Tanquetazo El Tanquetazo or El Tancazo ( both Spanish for " tank putsch " ) of 29 June 1973 are the names used to refer to the failed coup attempt in Chile led by Army Lieutenant Colonel Roberto Souper against the government of Socialist president Salvador Allende . It is called such because the rebelling officers primarily used tanks . It was successfully put down by loyal Constitutionalist soldiers led by Army Commander - in - Chief Carlos Prats . Background . By the beginning of June 1973 , an important part of the high command of the Chilean Armed Forces had lost all respect for the Popular Unity government of President Salvador Allende , which had been in office since November 1970 . During the so - called Tacnazo of 1969 , high - ranking officers had learned that by exerting pressure as a group , they could achieve wide - ranging changes within the military . In 1969 they had achieved high command changes and an increase in the Armed Forces ' budget . In June 1973 , some began plotting against the Allende government . A week before the coup attempt , the conspiracy was discovered at the Santiago Army garrison . The garrison commander , General Mario Sepúlveda Squella , informed his immediate superiors at the Army General Staff , and also told José Tohá , the Minister of Defense . The government immediately arrested nine people involved in the conspiracy , and Minister Tohá decided to go public with this information on the afternoon of 28 June . Putsch . Early in the morning of the following day , Lieutenant Colonel Roberto Souper , who had just learned that he would be relieved of his command for his part in the conspiracy , led a column of sixteen armored vehicles , including six Sherman tanks , plus eighty soldiers from the Second Armored Battalion in Santiago . The mutinous column rapidly traveled to downtown Santiago and encircled the presidential palace , La Moneda , and the building housing the Ministry of Defense , just across the Plaza de la Libertad . At two minutes before 9 : 00 AM , the tanks opened fire on these buildings . At the Ministry , a tank made its way to the main entrance , climbed the steps into the building , and started firing on offices . Sergeant Rafael Veillena , of the Army ' s Second Division , was killed when he looked out a ninth - floor window . The firing of machine guns and tanks panicked workers in the area , who at that hour were making their way to their jobs downtown . A woman working at the State Bank near the Ministry was killed in the gunfire , as well as a couple who were caught in cross - fire . At least 16 people were wounded , four seriously . A group of foreign journalists covering the reforms carried out by Allende ' s government was caught in the middle of the insurrection . While filming the events outside La Moneda , Argentine cameraman Leonardo Henrichsen and his colleague Jan Sandquist were fired at by corporal Héctor Hernán Bustamante Gómez and several soldiers . Henrichsen was fatally shot by a soldier , who was never identified . Before collapsing in the arms of Sandquist , Henrichsen recorded the military patrol firing at him . The footage was recovered by Sandquist and showed on the Argentine television on 24 July . General Mario Sepúlveda Squella immediately called General Guillermo Pickering , commander of the military institutes , requesting loyal troops to suppress the rebellion . After securing these troops , he called Army Commander - in - chief General Carlos Prats with a plan to neutralize Souper ' s forces . General Prats approved it immediately , and a few minutes later General Sepúlveda Squella started to position his own troops . Earlier that morning , Salvador Allende spoke to the people of Chile from the presidential residence at Tomas Moro in Santiago . In a 9 : 30 AM radio address , the president announced his unequivocal decision to defend the constitutional government against an attempted " coup d ' état " . He called upon the workers of Santiago to occupy the factories " and be ready in case it is necessary to fight alongside the soldiers of Chile . " In the meantime , General Prats visited all the nearby military regiments around Santiago to secure their support against the coup . The General encountered some resistance from the officers at the Junior Officers ' Academy , who claimed that they did not want to fire against fellow soldiers . Prats insisted that the insurrection against the constitutional government had to be put down , and as Army Commander - in - chief , he ordered them to the streets . After a brief moment of indecision , they chose to support him , and soon after 10 : 30 AM , combat - ready units from the Academy joined the fight against the rebels . Driving toward La Moneda , General Prats thought about the likely effects of these actions on other military units , who might be participating or , at least , waiting to act until they had seen the initial results . Prats decided to use all the resources available to crush the rebellion before noon . Near the presidential palace , General Prats left his car carrying a Thompson machine - gun . A large number of people had already congregated nearby , watching the movement of troops . Colonel Julio Canessa arrived with forces from the Junior Officers ' Academy , and General Prats ordered pieces of heavy artillery be deployed along the principal Avenue . He took what he subsequently called " a calculated risk " by speaking directly to the mutinous soldiers in an effort to convince them to give up their fight . Prats sought to prevent a long confrontation and unnecessary military and civilian casualties . According to his later account : " I then decided to advance in the company of Lieutenant Colonel Osvaldo Hernández , Captain Roger Vergara , and First Sergeant Omar Vergara . Extremely moved , Villaroel , the Military Chaplain , gave us the last absolution . " At 11 : 10 AM , the four soldiers walked along Alameda Avenue carrying assault weapons . When they reached the palace , they were within steps of Tank E - 2814 . The commander of the tank trained his machine gun on the group but did not fire . Prats ordered him to come down , identify himself , obey his orders , and surrender to the soldiers of the Junior Officers ' School . According to the account of a journalist watching the events nearby , " the soldier came down , stood at attention before the general , and saluted . That tank would not again fire against the Ministry of Defense or La Moneda on that morning . " Prats successively repeated these orders to the men in other tanks and combat vehicles located south of the Palace . When a soldier shouted from a tank : " I will not surrender , General ! " , while pointing his machine gun at Prats ' s group , Major Osvaldo Zabala approached him from behind and put a gun to his temple , disarming him and bringing the tense standoff to an end . A few of the tanks fled rather than surrendering after reinforcements from the " Buin " First Infantry Regiment arrived at the scene . This military unit , led by General Augusto Pinochet , quickly deployed its cannons and machine guns . The last rebelling unit to flee was a group of tanks and military vehicles stationed north of La Moneda . As this convoy fled south , General Prats saw Lt . Colonel Roberto Souper , " who looked disoriented and lost . " Immediately General Prats entered the palace and ordered a general search of the buildings nearby . General Pickering had cleared the rebels out of the western sector near the presidential palace . By 11 : 30 AM , the shooting around La Moneda had subsided , and the coup attempt appeared to be over . Aftermath . Souper surrendered later that day , after units from the " " Tacna " " regiment encircled and fired on the Second Battalion ' s barracks where he and his troops had taken refuge . Other military officers involved in planning the putsch were René López , Edwin Ditmer , Héctor Bustamante , Mario Garay , Carlos Martínez , Raúl Jofre , and José Gasset . It was soon discovered that the main leaders of the extreme right - wing group , Fatherland and Liberty , had been the instigators . Pablo Rodríguez Grez , John Schaeffer , Benjamín Matte , Manuel Fuentes , and Juan Hurtado sought asylum in the Embassy of Ecuador . From there they released a communique acknowledging that they had promoted the attempted coup . During the evening , President Allende addressed a massive demonstration of support in front of La Moneda . As he neared the end of his speech , he said : " " . . . trust your government . Go home and kiss your wives and children in the name of Chile . " " Though the " tanquetazo " was unsuccessful , it was a turning point in the deteriorating political situation of Chile . The failure allowed the conspirators to check loyalties , and push the government to take steps towards an alliance with the Christian Democracy party . Christian Democracy ' s leader Patricio Aylwin demanded the formation of a coalition cabinet , to include members of the armed forces . Allende rejected his proposal . The tanquetazo is seen as the prelude to the successful coup of 11 September 1973 . Amongst other consequences , Army Intelligence officers conducted a thorough study of the weaponry used against the rebelling troops , and the locations from which they where fired . Additionally , the strength of the so called " industrial belts " , traditional strongholds of pro - government workers , was accurately gauged and concluded to be weak , even after President Allende ' s call on all workers to defend the government .