As I thought more about dramatic irony, consider the story of 'Romeo and Juliet'. We know as an audience what happens behind the scenes. But Romeo only sees a dead Juliet. So he dies. Then when Juliet sees a dead Romeo, she also dies.

Then there is the story 'The Gift of the Magi' by O. Henry. If you've never read it, try this link:
https://www.lakes.k12.in.us/cms/lib/IN01001338/Centricity/Domain/325/Gift%20of%2...

A quite happier tale of irony,

Ah, love.