Irene McCormack was said to be a vibrant, determined and fun-loving girl. She received schooling from the Sisters of St Joseph. She went to boarding school at Santa Maria College, in Attadale Western Australia where she is said to have developed her two great loves: serving God and educating young people. By the age of 15 she had decided that she wanted to be a nun. She joined the Sisters of St Joseph in 1956 and spent the next few years teaching in country areas of Western Australia
After 30 years of teaching in Australian schools Irene made her decision that she wanted to serve the poor. She arrived in Peru in 1987 for missionary work. Irene's first assignment was in El Pacifico, a low income suburb in San Juan de Miraflores, Lima and Santa de Perola in Distrito de San Martín de Porres. On 26 June 1989, Irene left to serve in Huasahuasi, in the Andes Mountains about 200 km from Lima. irene, with her companion, Sister Dorothy Stevenson, were asked to supervise the distribution of emergency goods by Caritas Peru.
Irene continued her ministry of providing library facilities to poor children, who had no chance of obtaining books to aide in their school homework. She also trained extraordinary ministers of Holy Communion, as well as visiting the parishioners in outlying districts. On 17 December 1989, the priests of Huasahuasi were warned that they were in danger from Sendero Luminoso, so they and the two sisters left the village for Lima. Irene, however, felt that the church could not abandon the villagers at this time and returned on 14 January 1990. For 12 months Huasahuasi was without a resident priest. During this time irene and Dorothy Stevenson served the people, led the communion services and provided leadership for the people of the area.
From the convent, she was taken to the town square where 300 people had gathered. Earlier, the Shining Path terrorists had stormed the village, looted homes and terrorised the townspeople. Now, in the glare of spotlights Irene and four men were tried in a "kangaroo court" and sentenced to death.
Amid cries of "She's Australian, not a Yankee" and "Why kill these innocent people?" Sister Irene and the others were made to lie on the ground. The head terrorist gave the order and a young woman began shooting them, one by one. (Frances Atkinson, "The surprising life of Sister Irene", The Age, 24 March 2002.)
About 6 pm on Tuesday, 21 May 1991 an armed band of members of Sendero Luminoso entered the town of Huasahuasi. They threatened residents and entered a number of homes. Four men were taken from their homes and brought to the central plaza of the town. Members of the guerrilla band also went to the convent, where Irene was alone (as Dorothy Stevenson was receiving medical treatment in Lima). The Sendero Luminoso members did not enter the convent, but ordered Irene to come out, which eventually she did. She was also marched to the plaza and made to sit on the benches there with the four men.
For about an hour the five victims were harangued, interrogated and shouted at. Several local people interceded for the lives of the five, saying they were good people and not wrongdoers. Sendero Luminoso members retorted that they had not come for a “dialogue”, but to “carry out a sentence”.
Irene was accused of dispensing "American food" (Caritas provisions) and spreading “American ideas” (by providing school books). When local people insisted that Irene was Australian, not American, the guerrillas dismissed this as irrelevant. During the night, a group of young people from the village gathered around Irene in the darkness and managed to move her back into the crowd. But the guerrillas soon noticed her absence and returned her to the bench. Eventually the five prisoners were ordered to lie face down on the terrazzo-tiled surface of the plaza. Each was shot once in the back of the head. Irene was the first to be killed – about six metres from the door of the church. Since the bodies could not be moved from the plaza until authorities gave permission next morning, parishioners kept vigil by the body of Irne burning candles and praying. Then a group of women laid her out in the sacristy and did for her what their families did for the men killed with her. On 23 May 1991 a funeral Mass was held and Irene was buried in the Huasahuasi cemetery, in a niche donated by a parishioner.