The problem of the progressive collapse of a building has been addressed using a reinforced concrete flat slab frame. This structure was tested in the past at the ELSA laboratory to evaluate safety margins against collapse. Static linear and nonlinear analyses of the building under column removals had first been performed and then, in the experiment, columns had been successively removed, slowly demolished with a crunching machine. The experiment showed that the structure survived the demolition of two central columns, and also that structural testing against progressive collapse can be very challenging. Extending the scope, the dynamic nature of the loading has been considered in this report since buildings can be exposed to fast dynamic abnormal events, such as explosions or impacts, which may destroy abruptly load bearing elements. Thus, this study tries to answer the question of what would have happened to this building if the columns had been destroyed dynamically. For the same structural model dynamic linear and nonlinear analyses have been performed employing the finite element computational framework of the SAP2000 code. Alternately, three columns, a central and two corner ones, have been instantaneously removed and the structural response of the frame calculated. Maximum values of bending moments and forces at critical sections are reported and compared to those of the static analyses. Time histories of deflections of nodes above missing columns are determined, and several ratios of response parameters resulting from the different analyses are produced for comparison purposes. All approaches predict no mechanism which might lead to progressive collapse, even though several hinges are formed. Advantages of the use of static or dynamic, linear or nonlinear analyses are discussed.