Several people are reported to have died because of the 1938 Orson Wells Radio Broadcast of "War of the Worlds"

 The following Link takes you to the famous Orson Wells  radio broadcast of "War of the Worlds in 1938".

Reportedly 7 people died in cars in a panic and other reasons because they thought it was the real thing. So, ever since then the Government has thought a certain segment of U.S. citizens couldn't handle anything about UFOs without panicking and dying as a result. It is debatable how large this segment would be. However, people who believe in conspiracy theories already might or might not be in this category of among those who might die in panic if certain information is ever released that the government has regarding UFOs.

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• This incident in 1938 is often cited as the reason the U.S. government hasn't talked about UFOs much ever since then