The Maury Island incident
The account
Doughnut-shaped discs dropped metallic slag onto a boat, and a man in a black suit told the owner to keep quiet.
What investigators found
Military and FBI investigations concluded the story was a hoax and the slag came from a smelter.
The story
In June 1947, harbor patrolman Harold Dahl said six doughnut-shaped objects hovered over his boat near Maury Island. One of them allegedly dumped fragments of hot metal, injuring his son and killing his dog. Days later, a man in a dark suit supposedly showed up to warn him not to talk about it.
The case took a tragic turn when two officers carrying samples of the material died in the crash of the plane taking them home. Authorities, however, concluded that the slag was ordinary and that Dahl and his associate Fred Crisman had made up the story. Even so, it gave birth to the figure of the "man in black" in UFO culture.