Looks like they got the wrong building, instead...
The winter of 1978/1979 was very harsh in Poland, and due to the extreme temperatures and heavy snowfall it was dubbed "the winter of the century". Transport in the country came to a standstill, in poorly heated apartments in Warsaw the temperature at night dropped to 7 degrees Celsius, public mood was at a very low level, and the Warsaw poet Tomasz Jastrun, who kept a diary at that time, said: "People were expecting changes. They were convinced that the current situation had to come to an end, and something would happen. Before the change, people said, there would be signs. One of these signs was the Rotunda explosion".