calamitous (adjective)

1. In the fantasy novel, the calamitous defeat of the protagonist's army led to the fall of their kingdom.

2. The calamitous collapse of the old building highlighted the need for a more sturdy and reliable architecture design.

3. The film depicted a calamitous earthquake that devastated an entire city, leaving the characters to fight for survival.

4. In the comic book series, the calamitous invasion of extraterrestrial creatures threatened to annihilate humanity.