Father John Cornelius Troesch was a Maryknoll missionary. He was ordained on 21 May 1932 and served as Procurator of the missions in Hong Kong, Manila and Shanghai between 1937 and 1945.
Father Troesch was present in Hong Kong during the Japanese invasion. He was interned at Stanley Camp. In "Prisoner of the Japs", the author, Gwen Dew got to know the Fathers of the Maryknoll Order as they were interned in the same building as her. Father Troesch was in charge of their kitchen.
In September 1942, Father Troesch and other Maryknoll missionaries were released from Stanley Camp and later permitted to proceed to their mission stations in China. See here
Source
1. Maryknoll Archives: https://maryknollmissionarchives.org/deceased-fathers-bro/father-john-c-troesch-mm/
2. Ancestry website: https://www.ancestry.com/genealogy/records/john-cornelius-troesch-24-lm0t7m (DoB from Ancestry. Slight mismatch from Maryknoll Archives.)