Hanuš and Růžena Heim, the parents of Karel Hajek, were deported to the Terezín ghetto in July 1942.
In October of the same year they were deported from Terezín to the death camp in Treblinka.
Of the nearly 20,000 people deported from Terezín to Treblinka, two survived. Karel Hajek's parents were probably murdered immediately after their arrival.