Toni Zweifel was born on February 15, 1938 in Verona, Italy. His mother Antonia was Italian and his father, Giusto Zweifel, was a Swiss textile manufacturer. He was baptized on February 26.
Towards the end of his studies, through some fellow students, he came into contact with the newly opened Flüntern Student Residence, whose spiritual direction was entrusted to Opus Dei. He moved into the residence at the beginning of 1962. On March 19 of that year, he requested admission to Opus Dei. In June he finished his studies and immediately thereafter began his first job in private industry in Zürich.
In 1964 Toni became a member of the scientific team at the ETH Institute for Thermodynamics. Two years later he was also made director of the student residence. As part of his work there he organized annual introductory courses in the two Zürich colleges for graduates of the public high schools. During a workshop in Rome in 1970 he met Saint Josemaría, the founder of Opus Dei.
In 1972 his professional career took a new direction. He became the head of the newly organized Limmat Stiftung [Limmat Foundation] in Zürich. In the following 17 years, until his death, this Foundation helped in the development of hundreds of educational and social service initiatives in more than 30 countries on five continents.
In 1985 both of his parents died, his father in May and his mother in August. In the following year, on February 19, Toni learned that he was suffering from leukemia, for which he underwent chemotherapy treatment. After a temporary return to health, he suffered a first relapse in February 1988 and a second in the following November. In June 1989 he had to enter the hospital once more and undergo more chemotherapy. Toni died on November 24, 1989, and was interred in the Fluntern Cemetery in Zürich.
March 08, 2014