Frank Sinatra Jr. son of music legend and Rat Pack leader Frank Sinatra Sr. passed away today at the age of 72. His family released a statement to the Associated Press that died suddenly of a cardiac arrest in Daytona Beach, FL. Sinatra Jr. suffered the cardiac arrest while on tour promoting his "Sinatra Sings Sinatra." \u00a0Sinatra, Jr. was the son of singer and actor Frank Sinatra and his first wife, Nancy. He was the younger brother of actress Nancy Sinatra and the older brother of TV producer, Tina Sinatra. Sinatra Jr. was kidnapped when he was 19 yrs. old while living in Lake Tahoe,CA and his father had to pay $240,000 for his safe return. Later on Sinatra Jr. served as his father's musical director.