The 1979 explosion at PKO Bank Polski's Rotunda office in Warsaw took place on 15 February 1979, at 12:37 p.m. As a result, 49 people died and 135 were injured.

At 12:37 p.m., the bank's branch at the Rotunda, located in the city centre at the intersection of Marszałkowska Street and Aleje Jerozolimskie, was full of people.

The Zodiak restaurant offered hot meals to the rescuers, hundreds of liters of blood were collected, and witnesses remember terrifying scenes, such as a woman in a blue dress, without an arm.

The most common was the rumor about a bomb, planted by the main cashier of the bank, who had embezzled large sums of money and caused the explosion to destroy all evidence.

A similar rumor stated that the bomb was planted by cronies of a high-ranking Communist party official, who had stolen hundreds of thousands of zlotys.

Satirist Michał Ogórek says that people were also talking among themselves that the incident was part of an inner-party conspiracy, aimed at Edward Gierek and his cabinet.

One final rumor stated that the explosion was caused by a mysterious anti-Communist organization, which wanted to blow up the building at midnight, when it was empty, but messed up the timing.

Frozen water and snow clogged all the air vents, and in those circumstances, one spark or the turning on of a light in the basement, was enough to ignite the powerful explosion.

Edward Gierski, who commanded the search and rescue operation, also has doubts: "Despite all official reports and photos of damaged valves, I am still not sure if the explosion was caused by leakage in a gas pipe.

The project was overseen by a co-designer of the original Rotunda, Piotr Zajlich, who introduced several changes in construction, including with the wiring and the usage of offices.