Hart Crane
A modernist poet, Hart Crane became a leading figure in early 20th-century American poetry. His father was a wealthy chocolatier and candy maker. While the poet had a tumultuous relationship with his father, he became depressed when he had passed away. After Hart won a prestigious Guggenheim fellowship, he relocated to Mexico to write an epic poem. He boarded an ocean liner, headed back to New York. Around noon one day, he either jumped into the Atlantic Ocean or fell. He left no note and his body was never found.
Ian MacKintosh
The writer, less than a month before his 39th birthday, was on his way to Alaska, flying along with his partner and his friend. Just before 6 pm on July 7th, 1979, the pilot sent a distress signal. An air traffic control officer sent in the Coast Giard to help the approaching plane. When representatives arrived at the last reported position, there was no sign of a crash. The plane never landed, and the days-long search turned up nothing. The plane, along with its passengers, disappeared.