'On January 18, 1943, Nazis raid the ghetto again but this time the Jews resist. The Jewish Combat Organization stops the Nazi raids into the ghetto. Germans return on 19 April 1943, and the Warsaw Ghetto Uprising begins. In the intervening time, many of the ghetto residents construct hidden shelters or bunkers in the basements and cellars of the buildings, often with tunnels leading to other buildings. The handful of fighters who have weapons take to these shelters, giving the uprising the advantage of defensive positions.'

Well... that's a bit awkward!