After more than 20,000 phone calls, one induced labor, and thousands of angry letters, the UK's Broadcasting Standards Council convened for a hearing. On June 27, 1995, they ruled that the producers of Ghostwatch, a BBC program that aired on Halloween night less than three years earlier, had deliberately set out to “cultivate a sense of menace.”

Put another way, the BBC had been found to be complicit in scaring 11 million people senseless.

Airing from Northolt, North London, Ghostwatch alleged to report on the paranormal experiences of the Early family, which had been besieged by the actions of a ghostly apparition they called “Pipes.” Four recognized BBC presenters appeared on the show, which took on the appearance of a straightforward documentary and offered only subtle clues that it was an elaborate hoax. For a significant portion of viewers, it appeared as though they were witnessing documented evidence of a malevolent spirit.

Viewers grew so disturbed by the content that the network became embroiled in a controversy over what audiences felt was a ruse perpetrated by a trustworthy news source; cases of post-traumatic stress disorder in children were even reported in the British Medical Journal. What the BBC had intended to be nothing more alarming than an effective horror movie had petrified a country—and would eventually lead to accusations that it was responsible for someone’s death.

There is something of a myth surrounding Orson Welles’s infamous “War of the Worlds” broadcast of October 30, 1938. As the decades have passed, accounts of how Welles used the H.G. Wells story to fool a nation into believing aliens had invaded have become embellished. Listeners had supposedly become so infused with terror that they leapt from windows and suffered nervous breakdowns. Major cities had streets crowded with people craning their necks and looking for signs of a violent galactic attack.

While it’s true a number of people may have been disturbed by the “accounts” of military forces being overwhelmed by aliens, it’s unlikely to have been as widespread as later accounts would have it. Newspapers eager to browbeat the competing medium of radio exaggerated the show’s effect, then quickly dropped the matter; it’s not likely all that many people were even listening in the first place, with the program going up against a popular comedy show airing at the same time.

As perpetrators of hoaxes go, only Stephen Volk seems to have lived up to the standard Welles is thought to have set. A screenwriter, Volk pitched the BBC on a six-part series in 1988 about a roving paranormal investigation crew that climaxes in a live tour of a supposedly haunted house.

The BBC, however, wasn’t that enthused about devoting that much time to the idea. Instead, the pitch was condensed down to the last episode—a kind of “mockumentary” take on a paranormal occurrence that the channel could air as a Halloween special.

For Volk, it represented an opportunity to explore what he felt was the relative comfort of a television broadcast. Audiences went to horror films, he believed, knowing what to expect, consenting to being scared. But television was more intimate and less predictable. Viewers who tuned in anticipating a spoof or anticlimactic, tongue-in-cheek exploration would be in for a surprise—and not a pleasant one.

To add to the program’s credibility, Volk and director Lesley Manning structured it so two BBC presenters—Sarah Greene and Craig Charles—would be installed at the Early house, while highly regarded broadcaster Michael Parkinson would anchor from a studio. (Both Charles and Greene frequently popped up on BBC children’s programming, which would prove to be a lure when it came to an adolescent audience.)

Actors portrayed members of the Early family: single mother Pam and daughters Suzanne and Kim all reported instances of strange activity in their home, including rattling, mysterious cat noises, and smashed dishes. Suzanne would sport odd scratches on her face, which she claimed to be the work of Pipes, the ghost who refused to leave their home.

(In a testament to Volk’s commitment, he petitioned the BBC to allow him to try and insert a high-pitched warble on the soundtrack that would be audible to animals near televisions, hoping their bizarre behavior would unsettle viewers more. It proved to be technically impossible to do.)

Various ideas were batted around to reinforce the disclaimer, but few made it to the air. Mike Smith, Greene’s real-life husband and an on-air BBC correspondent who appeared on the special, once told the Radio Times that he suspected things might go south. “We had a meeting with the BBC days before transmission,” he said. “And we told them that this was going to cause a fuss. They told us not to worry because it was being billed as a drama in the Radio Times complete with a cast list. But we felt that wasn't enough."

By the time Ghostwatch premiered at 9:25 p.m. on October 31, 1992, the special had already been filmed, showing Parkinson reacting to segments and taking calls—all staged—that invited the audience to discuss their experiences with paranormal activity. In the interests of fairness, he also included an interview with a (fake) skeptic dismissing the Earlys’ claims.

Only highly observant viewers would have done the same. While the show began with a title card indicating it was written “by” Volk, the graphic was onscreen for only a split second; the presence of established and familiar faces to BBC viewers added to the verisimilitude. So did the program’s slow burn. At 90 minutes, it took its time, showing only fleeting glimpses into the Early family’s experiences that were left purposely ambiguous.

In the show’s second half, things took a turn. A viewer called in to tell them that someone had once committed suicide in the home; a mutilated dog corpse was said to be recently found nearby; the Early children were depicted as increasingly upset over the home’s disturbances. Around an hour in, Parkinson even advised viewers they’d be pre-empting scheduled programming to remain with Greene due to the "extraordinary" events taking place: Suzanne speaking in a baritone voice, and unseen cats mewling behind the walls.

Ultimately, Greene disappeared in the crawl space under the home’s stairs while a paranormal expert proclaimed that the television audience had unwittingly participated in a mass séance that had further emboldened Pipes. At the end of the show, Parkinson was seen being apparently possessed by the ghost’s spirit.

The finale laid it on a little thick, but not everyone made it that far in. By the time Ghostwatch signed off, a not-insignificant portion of the show’s 11 million viewers were either convinced ghosts were real, extremely upset at the BBC for traumatizing their children, or both.

The broadcaster had just five operators standing by its phones [PDF] once the show went off air, a number that was quickly overcome by the thousands of calls that flooded in. One woman reportedly went into labor due to the stress caused by watching the program; another reported her husband had soiled himself. Within hours, the BBC aired a brief segment that reminded viewers the show was fictional. It was a little too late.

Public discourse—including on the BBC’s own viewer feedback show, Bite Back—criticized the station for using its reputation to fool viewers into thinking harm had come to both the Earlys and to their hosts. Parapsychologist Susan Blackmore later said that “It treated the audience unfairly. It can be exciting to play on the edge of fantasy and reality, or stretch the accepted norms of television conventions, but this was neither true to its format nor fun. It was horrid to watch the distress of the girls, real or faked. I found it over-long and occasionally disgusting … The lack of adequate warnings was irresponsible.”

Greene quickly appeared on children’s shows to reassure younger viewers she had not been abducted or murdered by Pipes. Volk and Manning offered their own apologies, feeling that the BBC considered them pariahs. They had simply wanted to pay homage to Welles, never imagining the program could have the kind of effect it did.

In a report published in the British Medical Journal 18 months later, doctors in Coventry reported cases they classified as “post-traumatic stress disorder” from consumption of media—in this case, Ghostwatch. Two 10-year-old boys were suffering from panic attacks and sleep disturbances as a result of the broadcast. When the piece appeared, the Journal received correspondence from other doctors relating similar cases.

If not for his reported learning disabilities, 18-year-old Martin Denham might have been more psychologically equipped to deal with some transient nerves from the show. When he became distraught in the days following the broadcast, he began to grow concerned he might make contact with ghosts and committed suicide. His parents, Percy and April, blamed Ghostwatch, leading the Broadcasting Standards Council to rule that the show had been improperly labeled, with too few warnings that it was a fictitious premise.

Later, the handheld-camera, raw-footage approach would unnerve cinema audiences that flocked to films like The Blair Witch Project and the Paranormal Activity series. While those films rarely resulted in any claims more serious than motion sickness, Ghostwatch successfully married the BBC’s credibility with an effective ghost story to create an experience that’s unlikely to ever be duplicated.

Not that the network wants to try. Since its original airing, the program has never again been broadcast in its entirety in the UK.