Isaac Vischjager was a son of Jacob Vischjager and Vrouwtje Lelie. He was born in Amsterdam on 30 October 1903. After primary school, he went to the night school and got a job at a menswear company, where he eventually became a warehouse manager and were he was able to work for 23 years.
On 11 April 1935 he married Clara Witteboon in Amsterdam, a daughter of Abraham Witteboon and Vogeltje van West. Isaac and Clara had two children, viz. Leo, who was born on 16 March 1938 and Theo on 22 September 1942.
Clara Witteboon was the youngest of the three children in the family of Abraham Witteboon and Vogeltje van West. She had a brother Salomon and a sister Susanna, who both survived the war because of their mixed marriages.
After the wedding was concluded in 1935, Isaac Vischjager and Clara Witteboon moved into a house in the Boterdiepstraat 13 ground floor. There their son Leo was born. Early August 1940 the family moved to Uiterwaardenstraat 69 1st floor, where in 1942 their second son Theo was born,.
On 12 October 1942 Isaac Vischjager became a laundry clerk and a machine presser in the Dutch Israelitic Hospital (N.I.Z.) at the Nieuwe Keizersgracht 110. Through the Jewish Council, he became a member of the Jewish Society for Nursing and Care (JVVVV), for which he had an I.D. no. Z-0344. Isaac had no “official Sperre”, but due to his kind of work in the N.I.Z. and for the JVVVV, he and his family were only arrested and carried off to Westerbork on 29 May 1943.
After arrival in Westerbork, the family was housed in barrack 64, waiting for their deportation. That followed on 1 June 1943, when Isaac Vischjager, his wife Clara Witteboon and both their children were put on transport to Sobibor. This transport was one of the largest of all 19 deportation trains to Sobibor: it contained in total 3006 deportees, of which Jules Schelvis was the only survivor.
All other victims, among them Isaac Vischjager, Clara Vischjager-Witteboon and their two little sons, the 5-year old Leo and the 8-months old Theo Vischjager have been immediately murdered in the gas chambers there upon arrival on 4 June 1943.
Sources include the City Archive of Amsterdam, family registration card of Abraham Witteboon, archive cards of Isaac Vischjager,f Clara Witteboon and Leo and Theo Vischjager; the file cabinet of the Jewish Council, registration cards of Isaac Vischjager, Clara Vischjager-Witteboon, leo and Theo Vischjager and the Wikipedia website Jodentransporten vanuit Nederland.nl.