Prior to participating in World War I, Sidney Johnson Brooks became the first flying cadet to lose life during training in San Antonio, Texas. Beforing volunteering for the Army, Brooks was a part time reporter for the San Antonio Light Newspaper. After his completion into officer training school, Brooks entered the Army Signal Corps Air Service and begun his flight training at Kelly Field, San Antonio, Texas.

On November 13, 1917, Brooks embarked on his first solo flight. Upon approaching to land at Kelly Field, Brooks lost consciousness and plummeted to his death according to some observers. Reports later revealed that Brooks might of suffered from severe secondary effects from an influeza vaccination that he recieved that morning.