Tā de lǔmǎng xíngwéi zuìzhōng niàngchéng le zāihuò.
His reckless behavior ultimately led to catastrophe.
Tips
usage
灾祸 combines 灾 (natural disaster) and 祸 (misfortune/calamity), and can refer to both natural and man-made catastrophes. Slightly more literary than 灾难 (zāinàn).