John F. Kennedy Jr., the only son of President John F. Kennedy to survive infancy, was killed in a plane crash on July 16, 1999 off the coast of Martha's Vineyard. He was only 38 years old at the time. His wife, Carolyn Bessette Kennedy, and his sister-in-law, Lauren Bessette, were his passengers and also died. They were on their way from New Jersey to his cousin Rory Kennedy's wedding.

The National Transportation Safety Board concluded after a year-long investigation that Kennedy's "failure to maintain control of the airplane during a descent over water at night, which was a result of spatial disorientation. Factors in the accident were haze and the dark night."

Like the death of Kennedy's father, his own death has been at the center of conspiracy theories. Some suggest that this was no accident and that he was murdered. As recently as April 2016, Roger Stone, who supports Donald Trump in the 2016 election, suggested that the Clintons murdered Kennedy. Click through for a look at some of the conspiracy theories surrounding Kennedy's death. Most of these center on the rumors that Kennedy was considering a run for political office, which could have changed the trajectory of U.S. politics if he lived. (Getty)