His older brother [Joseph P. Kennedy, Jr.] had been expected to be the family’s political standard bearer, but he was killed in action during World War II.
That is incorrect as "in action" presumes killed by enemy action. He was killed when the initial operational flight of a experimental drone system exploded prematurely. Just more of the Kennedy literal myth making.
Remembering the Death of Lt. Joe Kennedy Jr. and America’s First Combat Drones