Which event is marked by 20 June 1913?

The event marked by June 20, 1913, is significant as it commemorates the first aviation death. This moment holds historical importance in the context of early aviation, as it highlights the inherent dangers associated with the nascent field of flight during that era. The individual involved was a pioneering aviator whose tragic accident underscored the risks that early pilots faced as they experimented with and advanced the technology of flight.

While the other events listed are important milestones in aviation history, they do not correspond to this specific date. The first take-off from a ship occurred later in aviation's timeline, as did the implementation of formal flight training programs and the establishment of the Naval Aviation School. These milestones all played a crucial role in the evolution of naval aviation, but June 20, 1913, is distinctly remembered for the first aviation fatality, marking a sobering moment in the history of aviation.