SALVATORE CALABRO, 38, of New York, was a firefighter who loved to read about the history and heroes of World War II and the Vietnam War. Always patriotic, he was wearing an American flag patch on his uniform when he responded to the World Trade Center attacks. ``The flag was on his uniform sleeve and his turnout coat. He was a real American,'' said his wife, Francine. A 14-year veteran of the Fire Department, he loved his job but he was happiest watching his young sons grow up. ``He was an unbelievable dad,'' his wife said.