The second child in the Kintzel family, Tadeusz was the older brother of Danuta (Diana). He bravely risked his life to assist Diana, and her husband Stanley Steyer, in hiding Jews on the Aryan side of Warsaw. He was about 29 years old at the time, and a chemical engineer by training. Tadeusz has yet to be recognized as one of the “righteous among the nations.”

In 1948, Tadeusz got married, and he and his wife Hania subsequently had two daughters. Tadeusz remained instrumental in helping Diana and Stanley even after they left Poland–for example, in obtaining a copy of their wartime marriage certificate. Tadeusz lived in Warsaw for the rest of his life.