During the German Occupation, Bosch set up underground press and resistance networks, which notably helped save hidden people and Jews.

[2] While the Netherlands were occupied by Nazi Germany, she established an underground press group called De Vonk, using her existing networks.

[2] Her group was not only involved in the publication of clandestine newspapers but also made contact with people in hiding to provide aid and distributed Resistance propaganda.

[2][3][4] The anarchist managed to clandestinely pass her notes out of the prison, alerting a number of individuals targeted by the investigations.

[2] On 17 February 1945, she was selected to be gassed in the nearby Uckermark camp, but after a technical failure of the gas chambers, the Nazis decided instead to execute the group by shooting.