On Oct. 31, 1938, newspapers across the country devoted big chunks of their front pages to stories about a radio broadcast the night before.

There was other news. President Franklin D. Roosevelt was trying to prevent a railroad workers' strike. A Utah man executed by firing squad was wired up to show "the action of the human heart pierced by bullets." Men had lined up to serve as jurors in a Hollywood trial of fan dancer Sally Rand, apparently in the hope she would perform in court.

But the radio show was something else. It was blamed for fainting spells, heart attacks and a nationwide wave of hysteria.

On Oct. 30 those 75 years ago, showman Orson Welles had flipped out significant portions of America with his radio play "The War of the Worlds."

Welles, 23, had not yet shaken up cinema history with "Citizen Kane," but had already established a reputation as a wunderkind in theater and radio. As part of Welles' Mercury Theatre radio programs, writer Howard Koch adapted "War," then a 40-year-old tale by H.G. Wells, in which Martians invaded England and were stopped only when an Earth bacteria infected them.

For the radio version, the location was changed to America, with the names of real towns, including the invasion site of Grovers Mill, N.J. Mercury producer John Houseman further told Koch to present the story as a series of news bulletins, heightening the tension and the realism.

Not without warning

The broadcast began with the announcement that it was a radio play, and other notices would come. But some listeners tuned into the show while it was in progress, missing the opening. And despite the annoucement, the show itself felt real, full of urgency and fear.

As a result, many people sitting by their radios, already jittery about the clouds of war forming over Europe, believed that Martians had invaded not only New Jersey, but also the rest of the nation.

Jack Paar later said he was working as a radio announcer in Cleveland the night that "War" aired. While his account in his memoir "I Kid You Not" is wrong on some details, Paar nonetheless said the switchboard lit up and he tried "telling the alarmed listeners that the invasion was fictional.

"I also broke into the program to announce this," Paar said, "but the calls kept pouring in, many of the panicky callers charging that I was covering up the truth."

Then the true truth was known, when Welles firmly told the audience this was all just a Halloween tale "jumping out of a bush and saying 'Boo!' "

Police investigated, the Federal Communications Commission examined it, and officials complained. Commentators weighed in, Welles expressed surprise and later regret, and an academic study tried to figure out who believed the broadcast and why.

Questioning what is real

Welles' production is often held up as an example of art faking reality. To be sure, in the years since 1938, some have questioned whether "the panic broadcast" was really as widespread a sensation as it seemed. While a 1940 study of the response to the broadcast leaned heavily on interviews with people "selected because they were known to have been upset by the broadcast," a 2011 analysis for the Radio Journal argued instead that "War" provided a demonstration not of panic but of "a kind of social networking."

Surprised and even frightened by the broadcast, people tapped into their "social networks" of families and friends, as well as "social authorities and mass media" for information, the authors of the study wrote.

But even very real horrors may straddle, at least momentarily, a mental line between belief and disbelief. Because "War" was so convincing, then and now, it contributes to people's doubts even about the truth.

In the Journal of Scientific Exploration, German author Gerd Hovelmann wrote that his first thought upon hearing about 9/11 was "Orson Welles."

Though he knew Welles had died long before those terrorist attacks, Hovelmann thought, "Just like back then [in 1938], everything sounds both realistic and at the same time unreal."