Fifth in a series of articles around the anniversary of the death of Vladimir Ulyanov (Lenin) in 1924 In December 1877 an explosion occurred at one of the St Petersburg armaments factories. The workers there believed it to be due to the negligence of the management. Six workers were killed. An organised group of politically conscious workers had existed in the factory for some years. Stepan Khalturin, who would be the main organiser of the Northern Union of Russian Workers and who would be hanged for an attempt to kill the Tsar, had worked there.