The Thalidomide tragedy was a pharmaceutical disaster in the late 1950s and early 1960s, where the drug Thalidomide, initially marketed as a sedative and treatment for morning sickness in pregnant women, caused severe birth defects in thousands of children worldwide. This event led to significant changes in drug regulation and testing, emphasizing the need for rigorous clinical trials and the establishment of more stringent drug approval processes to ensure safety and efficacy.