RESUMO
The paper presents the results of a cross-sectional study conducted in Mexico City following the earthquake that occurred on September 19, 2017. The sample size of the study was N = 2400. The aim has been the study of people's emotional and behavioural responses during and immediately after the tremors. Some of the results and conclusions were the following: a). During the tremors, respondents coping reactions were related to escape, reaching and protecting people, and seeking shelter; b). The actions taken by the respondents immediately after the tremor were reuniting with family members, evacuation, and returning to houses; c). The emotional responses of the participants of the study were fear and surprise; d). The capital city's residents exhibited a relatively high percentage of prosocial behaviour during the seismic emergency response; e). More generally, the residents of the city should be trained on what to do during and after the tremors; moreover, key decision-makers should consider people's emotional and behavioural responses to tremors when designing plans for mass emergencies following earthquakes, such as the present case study.