After the Allied landing on D-Day, living conditions grew worse, and Arnhem was subsequently heavily damaged during Operation Market Garden. During the Dutch famine that followed in the winter of 1944, the Germans blocked the resupply routes of the Dutch people's already limited food and fuel supplies as retaliation for railway strikes that were held to hinder German occupation. Like others, Hepburn's family resorted to making flour out of tulip bulbs to bake cakes and biscuits; she developed acute anaemia, respiratory problems and oedema as a result of malnutrition. The Van Heemstra family was also seriously financially affected by the occupation, during which many of their properties, including their principal estate in Arnhem, were badly damaged or destroyed.