In seismically active regions, many major earthquakes consist of multiple strong shocks occurring over short timeframes and limited areas, increasing the risk of cumulative damage, especially for brittle structures like masonry heritage buildings. These repeated shocks often strike before inspections or stabilisations can be carried out, leading to worsening structural conditions. Dramatic examples of this accumulation, often even caught by television cameras, such as the collapses of the smaller tower of the Foligno town hall or the tower “dei Modenesi” in Finale Emilia, illustrate the destructive impact of such sequences on masonry towers, a structural typology characterised by a significant seismic vulnerability. While large-scale seismic risk studies have advanced, cumulative damage has mostly been explored through numerical models, with limited empirical research. The difficulty lies in linking observed damage to specific shocks due to sparse data. A promising approach involves distinguishing assets struck by single versus multiple events using geographic and intensity data, enabling more accurate vulnerability modelling that accounts for overlapping seismic effects. Although masonry towers are frequently part of larger buildings, their unique structural characteristics make separate seismic vulnerability assessments an essential and viable approach. This study investigates the cumulative damage effects of the prolonged Central Italy earthquake sequence on masonry towers, using a comprehensive database of post-disaster surveys. It develops vulnerability and fragility functions to model and predict average damage and its likelihood, distinguishing between towers impacted by a single main shock and those affected by multiple shocks.