We conducted a survey of over 2000 people before and after the Great East Japan Earthquake and obtained valid responses from 840 participants who completed both surveys. Participants responded to two types of trolley problems and answered a series of sociodemographic questions. As in previous studies, more than 80% of participants responded that they would push the switch (utilitarian judgment), and only less than 45% of participants chose the utilitarian option in the modified version (i.e., pushing to drop the person to stop the trolley). We found that people were slightly less likely to flip the switch after the earthquake than before. In addition, people who believed the world was trustworthy and who had a greater sense of self-control were more likely to flip. The results are discussed in terms of the flexibility and adaptability of external environmental factors and their possible effects on moral judgments.