several school buildings have collapsed during past earthquakes killing many children and teachers. venezuela has not been absent from this situation, as was demonstrated in 1997 when an ms=6.8 earthquake lead to the collapse of four school buildings, two of them belonging to the raimundo martínez centeno high school. the structural failure consisted in the collapse of the first story, leaving the slab of the first floor resting on the ground. nonlinear dynamic analysis techniques, based on damage concentration on critical sections of the structure, were used to identify the causes of the collapse. the infill walls and the stairs significantly influence the dynamic properties of the building, reducing the vibration periods. the values defined in this work as yield story drift and ultimate story drift from a nonlinear static analysis (pushover) were found to be good estimators of the damage threshold and the collapse threshold during the dynamic response, respectively. the nonlinear dynamic response to accelerograms representing the seismic motion is characterized by a concentration of deformation at the first story that exceeds the tolerable drift values; the instability is initiated in the central frames due to the shear brittle failure of the short columns at the first story, created by the infill masonry walls inside the frames that had wide openings at the top.the failure mode resulting from the analysis is consistent with the observations at the site. a large deformation at the first story that leads to the collapse of the building is also observed when the infill walls were removed and the analysis was repeated. the collapse of both buildings was the result of the limited capacity to resist lateral loads and to dissipate energy, together with the presence of short columns that precipitated the brittle failure modes of the structure, which are typical of buildings built with old earthquake-resistance design codes.