Situational irony is when the opposite happens than what is expected. For instance, an ambulance picks up people from a car accident. On the way to the hospital, the ambulance is struck by a car and everyone dies. Yikes! I know. This is situational irony. Click here for a quick video of situational irony.
Verbal irony...think Sarcasm. However, verbal irony implies a different meaning to what is actually said, sarcasm is mainly used as a sharp and direct utterance designed to cause pain. Click here for a quick video of verbal irony