Sarcasm – hurtful irony
Sarcasm is a form of irony meant to attack, mock, ridicule and generally hurt someone.
The Russian Tsar was thrown into a chasm (sarcasm) by the leaders of the revolution. They threw iron (irony) bars at him which really hurt, and he died a painful death.
Some examples of sarcasm where the irony hurts
Sorry for being late, I got caught up enjoying my last few minutes of not being here.
Children really brighten up a household – they never turn the lights off.
NOTE:
The distinction between irony and sarcasm can depend on the tone of voice. If the tone sounds hurtful, then it is sarcasm.