What happened
Harold Dahl claimed that on June 21, 1947, while out in a boat near Maury Island, he saw six ring-shaped objects, one of which dropped a shower of hot, metallic slag – the fragments supposedly killed a dog and injured Dahl’s son. His superior, Fred Crisman, presented the “debris” to publisher Ray Palmer, who asked Kenneth Arnold to investigate. Arnold called in two military intelligence officers, Captain William Davidson and Lieutenant Frank Brown. They listened to the men and took samples, and on August 1 their B-25 bomber crashed after taking off from McChord Field – both were killed. The press speculated about sabotage, and the story became one of the first conspiracy threads in ufology.
Witnesses
Harold Dahl and Fred Crisman; no accounts by other witnesses are known.
Explanations and hypotheses
The FBI and military intelligence concluded that the affair was a hoax. According to FBI documents, Dahl and Crisman admitted that the slag was ordinary waste from a smelter and that they had made up the story to sell it to Palmer. The B-25 crash was an ordinary accident – an engine caught fire. Conspiracy theorists cite Crisman’s later colorful biography, but this does not change the assessment that the incident was a fraud.
Hoax A proven or admitted hoax.
More: Wikipedia (en)