Irony deals with opposites; it has nothing to do with coincidence.
If two baseball players from the same hometown, on different teams, receive the same uniform number, it is not ironic. It is a coincidence. If Barry Bonds attains lifetime statistics identical to his father's, it will not be ironic. It will be a coincidence.
Irony is "a state of affairs that is the reverse of what was to be expected; a result opposite to and in mockery of the appropriate result." For instance: a diabetic, on his way to buy insulin, is killed by a runaway truck. He is the victim of an accident. If the truck was delivering sugar, he is the victim of an oddly poetic coincidence. But if the truck was delivering insulin, ah! Then he is the victim of an irony.
If a Kurd, after surviving bloody battle with Saddam Husseins army and a long, difficult escape through the mountains, is crushed and killed by a parachute drop of humanitarian aid, that, my friend, is irony writ large.