Which word describes something that is disastrous in outcome?

The word that describes something with a disastrous outcome is "calamitous." This term specifically refers to events or situations that lead to significant harm, destruction, or suffering, emphasizing the severity and negative consequences involved. It is often used in contexts like natural disasters, accidents, or catastrophic events where the results are highly unfavorable. In contrast, other choices denote positive or fortunate outcomes, which do not align with the concept of disaster.