A teacher asks her students to…

A teacher asks her students to discuss what their dads do for a living.
Little Mary says: “My Dad is a lawyer. He puts the bad guys in jail.”
Little Jack says: “My Dad is a doctor. He makes all the sick people better.”
All the kids in the class had their turn except Little Johnny. The teacher says: “Johnny, what does your Dad do?”
Johnny says: “My Dad is dead.”
“I’m sorry to hear that, but what did he do before he died?”
“He turned blue, and shit on the carpet.”