Sotto un cielo di piombo. Le lotte per la casa in una borgata di Roma. San Basilio, settembre 1974 - Social struggle for housing in Rome has produced a movement which has endured over 50 years of Italian history. Squatting is the unavoidable answer for a large number of people to the lack of houses due to building speculation, to the problem of the renewal of the suburbs built during the fascist regime, to the heavy wave of immigration and to the absence of city planning. Due to problems of overcrowding and lack of transparency in establishing allotment lists, the occupation of the San Basilio suburbs in 1974 ended tragically in the death of a young demonstrator and dozens injured among the police and the occupants. The author of the article argues that the occupation of San Basilio culminated in an armed conflict for three reasons: 1. The endeavour could have become a model of conduct for the whole country; 2. Engaged in realizing the Historic Compromise policy, the Italian Communist Party could not tolerate such radical forms of struggle in its left wing; 3. Some of the militants of the extra-parliamentary Left took these conflicts as an opportunity to intensify their battle against the State, starting an armed conflict in organisations such as the Red Brigades and Prima Linea. The article is structured on the oral evidence of the people involved. Key words: The suburb of San Basilio, Suburbs of Rome, Occupations of houses, Fabrizio Ceruso, September 1974, Lotta Continua.