A man and his young son are driving to the city. On their way over the traintracks, the car stalls. Before the son and man can get out, they are hit by the train. The man is instantly killed (the examiner pronounced him dead upon impact), while the son, while horribly injured, remains alive.
The son is rushed to the hospital, where the doctors decide he needs surgery right away if he is to live. He is rushed to the OR, where the he waits for the surgeon. The old surgeon hobbles in, takes one look at the boy, and says, "I cannot operate on this boy. He is my son."
How is this possible?