During the Nazi occupation of Poland, Józef Trębacz lived in Chrzanów, Kraków District, with his wife Waleria and their eight children and grandchildren. Józef owned a brick manufacture business, and Waleria worked family's farmland.
On February 21st, 1943, three days after the final liquidation of the Chrzanów ghetto, Pinkus Jakubowicz, a pre-war Jewish acquaintance of Józef’s, knocked on their door, exhausted and suffering from hypothermia. Formerly a well-to-do resident of Chrzanów, he had moved with his family to Tarnów before the war, and managed to send his children abroad as soon as the war began. He and his wife, however, were among the Jews deported from Tarnów to Auschwitz. When the transport reached the environs of Chrzanów, the couple managed to jump out of the train. Pinkus’ wife was shot by the guards, and Pinkus escaped, walking through the fields until he reached the Trębaczes’ home.
Józef Trębacz immediately agreed to take Jakubowicz in. With his being the authoritative person of the family, his decision was not challenged by anyone. He built a hideout for the fugitive, and continuously improved it so as to ensure that it was as safe and comfortable as possible. Waleria provided his meals, despite the shortage of supplies and the many mouths the large family had to feed, and the children ran errands and were on the lookout; their warnings saved Jakubowicz more than once from unexpected visits by the Germans and their collaborators who kept searching the area for partisans, particularly a certain Hans Reilich, who arrived at the house more than once, citing the need to check the house for fire proofing etc. When Jakubowicz contracted pneumonia, a doctor was brought in to treat him. The physician was told that Jakubowicz was a cousin. Józef went as far as to give the sick man his own bed. During the entire period, the Trębacz family and their ward lived with fear that Jakubowicz would be spotted by the customers who came to buy bricks or thatthe neighbors, who seemed to suspect the family was hiding Jews, would denounce them.
Pinkus Jakubowicz stayed with the Trębaczes until January 10th, 1945. After the war, Jakubowicz traveled to Belgium to see his son, then to France where he stayed with his daughter. Finally, in 1962, he immigrated to the USA, settling in New Jersey with his daughter Bronisława and her husband. He continued to correspond with the Trębaczes until Józef’s demise in 1968. Jakubowicz died in 1976, but his daughter kept in touch with Trębacz’s daughter.
On January 8, 2008, Yad Vashem recognized Józef Trębacz and his wife, Waleria Trębacz, as Righteous Among the Nations.