Incomplete question. I provided an explanation about irony in literature.
Step-by-step explanation:
Situational Irony is a literary device used by an author to express an action in the plot of a story that is totally different from what the reader would expect.
For example, a protagonist (the leading character) in a story with so much life in one story unexpectedly and tragically died. This is ironic because the reader would naturally expect the protagonist to save the day.