The January Self-Defence resulted in the implementation of military training for youths (conspirators of the Jewish Combat Organization and the Jewish Military Union) and the establishment of shelters, hideouts, and so-called bunkers; the latter proved their worth only a few months later, during the uprising.
The Jews also built passages between buildings, and even tunnels under the ghetto wall. Food was stocked, and efforts were made to acquire weapons. The civilian population was asked to involve itself in the construction of shelters and underground tunnels. Researchers of the Holocaust have located more than eighty bunkers and shelters on the area of the former ghetto.
Jürgen Stroop’s infamous report, too, contains information about a network of bunkers that formed an underground city, of which the Germans had no previous knowledge. He wrote thus:
“It has turned out that the Jews hid themselves in the sewers and in specially furnished bunkers. Initially, we assumed that there were only individual bunkers, however in the course of the action it transpired that there was an organized system of cellars, bunkers and passageways throughout the ghetto. Each passage and bunker had access to the sewage network. This allowed the Jews to move freely underground”.
Many of the structures were equipped with toilets and sleeping places for several people, and also had stocks of food that would have allowed their inhabitants to survive for even a few months. Stroop also wrote that 631 such hiding places had been liquidated by the end of the uprising.
In fact, every space was appropriate for establishing a shelter. Some were located in cellars, others in attics, under stairs, and even in living rooms – behind wardrobes, built-in walls, etc. Other shelters, situated mainly underground, were built to provide protection for larger numbers of people. There are few extant sources of information on the conditions which existed in these hideouts. The testimony of a woman named Maryla is particularly valuable. She wrote down her impressions while still in the ghetto, also during the uprising. In one of her entries, she stated:
“I left the bunker – this escape to the grave while still alive – as my last resort. Recently, however, I started to reconcile myself to the idea that it will be necessary to hide in the bunker. But I was thinking of it as of a somewhat distant future […]. During the night, then, there commenced a feverish race to the shelters, with bundles and possessions, and with life made so dear by the constant placement of death right before our eyes. So many people had already gathered in the shelter that the air was a dense mixture of human effluvium, and it was impossible to draw any oxygen. The number of those gathered exceeded what the bunker could accommodate, and thus the ventilation was wholly inadequate [x], the air so deprived of oxygen that you could not even light a match. I was present in this dungeon [x] when it was being finished and was not yet populated. I remember that at the time I had populated it in my mind, and that it sent shivers down my spine to even think that it could one day be our home.”