THE mystery of the fainting Blackburn schoolgirls will be the subject of a TV investigation on Friday night.

Uncanny, presented by Danny Robins on BBC Two, will explore the circumstances which surrounded the mass faintings which saw scores of pupils from St Hilda’s Girls’ School simply keel over in October 1965.

Fleets of ambulances were brought in to ferry the stricken pupils to Park Lee Hospital where special isolation wards had to be opened and mattresses laid out on the floor to cope with the numbers.

Lancashire Telegraph: A fainting victim is taken away by stretcher in October 1965

The drama unfolded over a period of several days, beginning with the visit to Blackburn of Princess Margaret who was to re-hallow the nave at the cathedral.

More than 800 schoolchildren were waiting to greet her in the cathedral grounds but fog had delayed the royal flight and she arrived more than 90 minutes late.

One by one, youngsters who had been waiting at this stage for more than three hours started to faint.

The hot weather was blamed for the initial outbreak but the mystery deepened the following day when St Hilda’s pupils continued to pass out seemingly without reason.

In one day, 98 pupils were affected with one ambulanceman telling the Lancashire Evening Telegraph at the time: “As fast as we took them away, new cases from classrooms in other parts of the school were being brought in.”

Thirty five pupils were kept in hospital overnight.

Further pupils were affected over the weekend leaving health officials mystified.

Lancashire Telegraph: Dramatic scenes at Blackburn Catherdral as 140 choolgirls collapsed waiing for the arrival of Princess Margaret in 1965

An investigation of the school premises began and on the Monday, a further 54 cases were reported leading to the school premises being closed.

Preparations were made to fumigate it as doctors and health inspectors delved in the drains, scraped paint from the walls and furniture, took water samples and even sent off snacks from the school’s tuck shop to their laboratories.

“We are becoming more like detectives than the CID themselves,” said deputy medical officer Dr John Mountain, who with his team recorded interviews with the ‘victims’.

Speculation about the cause was rife with even aliens being blamed for the incident.

Investigations led to medical officer of health Dr John Ardley theorising that that fumes from two nearby factories and from the school’s boilers were partly to blame. But he admitted they were not enough to put anyone in hospital unless they had been subjected to other stresses.

He listed possible ways in which girls had been “conditioned.” One was worry about the polio epidemic that claimed more than 50 victims in the Blackburn area that summer - and taking the actual vaccine.

Another was that most of the girls had stood without drinks for three hours in a hot, humid atmosphere for the royal visit.

Lancashire Telegraph: Dramatic scenes at Blackburn Catherdral as schoolgirls collapsed waiting for the arrival of Princess Margaret in 1965

Finally, there was the experience of seeing fellow pupils collapsing in school the next day.

“In such circumstances,” he concluded, “it was not difficult for the toxic fumes to trigger off symptoms in the more-susceptible pupils.”

But more than a year later, his opinion was challenged in a report in the British Medical Journal by Blackburn consultant paediatrician Peter Moss and by a London psychologist.

They said mass hysteria was responsible for an “epidemic of over-breathing.” They, too, pointed to the polio epidemic, saying that it had rendered the population emotionally vulnerable and added that the wait at the royal visit, which caused 20 girls to faint, had been a trigger for what followed.

“The next day, on the bus to school, one teacher noticed an air of excitement and a great deal of talk about fainting - exactly who had fainted and how many times. The scene was set,” said their report.

Lancashire Telegraph: Uncanny presenter Danny Robins with experts Dr Ciarán O'Keeffe and Evelyn Hollow (Picture: BBC)

Now 58 years after the event, Uncanny will set out to determine what really happened and photographs taken at the time by the Lancashire Evening Telegraph will feature in the programme. Joining Danny Robins - who wrote the hit West End play 2:22 A Ghost Story - are Dr Ciarán O’Keefe and parapsychologist Evelyn Hollow.

Uncanny is on BBC2 on Friday at 9pm