Long before the outbreak of the uprising in the ghetto, the basement of the tenement at ul. Miła 18 was being used by a group of smugglers led by Mojżesz Kulas and Srul Iser. There, they organised a hiding-place where they could store goods smuggled into the ghetto from the “Aryan side”. The hiding-place consisted of several large rooms, with camouflaged hatches and ventilation. Water and electricity had also been connected. The bunker also had six exits. It served to provide help to all fighters and civilians who found shelter in that tenement basement at Miła 18.