man-made disaster; human-caused calamity
Refers to disasters caused by human error, negligence, or intent, as opposed to natural disasters (天災). Often used in contrast with 天災.
This accident is not a natural disaster but clearly a man-made one.
To prevent man-made disasters, thorough safety measures are necessary.
人災 means a disaster caused by human error or negligence, directly contrasting with 天災, which is caused by nature.
Compound of 人 (じん, 'human') and 災 (さい, 'disaster'). The reading is on'yomi, and the word is a straightforward Sino-Japanese compound.