Deutsch began acting at the HNK Zagreb at the age of five, playing small roles in professional productions of Molière and Shakespeare.

In 1941, the Independent State of Croatia (Croatian: Nezavisna Država Hrvatska, or NDH) began the implementation of race laws which prevented Deutsch from acting.

In the coming days, Croatian and German officials began detaining the heads of the Jewish community in Zagreb and any remaining Jews who had been allowed to stay in the city up until that point.

Actors Tito Strozzi, Vika Podgorska, and Hindko Nučić, and the theatre's attendant Dušan Žanko (himself a member of the Ustaše) all attempted to save Deutsch's life.

[5] In the lower floor of their house, the Deutsch family had at one time a tenant, a young man from Herzegovina, who occasionally wore the Ustaše uniform.

In the words of Deutsch's friend Nika Grgić, this young man offered to falsely marry Lea in an attempt to save her from deportation, but that was not done for unknown reasons.

Her father, Stjepan, managed to save himself, hiding as a patient who suffered from infectious ocular trachoma at the ward of an ophthalmologist, Dr Vilko Panac, in the Sisters of Charity Hospital, Zagreb.