The irony of situation takes place when what actually happens is in stark contrast to something that was expected to happen. The most famous example of situational irony is a poem by Coleridge titled 'The Rime of the Ancient Mariner' which is:
Water, water, everywhere,
And all the boards did shrink;
Water, water, everywhere,
Nor any drop to drink.
The irony of the situation is that although there is plenty of water everywhere it cannot be used for drinking. The situational irony is used by Anne Tyler in her literary work titled 'The Accidental Tourist' when she writes the following lines:
"Seated in a stenographer's chair, tapping away at a typewriter that had served him through four years of college, he wrote a series of guidebooks for people forced to travel on business."