Final agony of RAF volunteer killed by sarin - in Britain.
As the inquest into the death of a 'human guinea pig' at Porton Down opens, a witness breaks 50 years' silence to recount the horrors he saw...
Like most 19-year-olds, Alfred Thornhill had never seen anybody die. When the fresh-faced trainee engineer from Salford answered his call for National Service, he thought he could handle anything.
Dispatched to the ambulance service, the self-confident teenager arrived for a month-long posting at Porton Down, the Government's top-secret chemical weapons laboratory in Wiltshire. He was proud to be doing his bit for his country.
But nothing could have prepared the young Mancunian for the horrific events he witnessed on a May morning in 1953. Answering an emergency call, he witnessed scenes which would haunt him for half a century and thrust him to the centre of an inquiry into one of the darkest hours of British military history.
Until today Thornhill - now a 70-year-old pensioner - has never spoken publicly about what he saw. He feared the Ministry of Defence would send him to prison.
He has now broken his silence to tell of the day he arrived at Porton Down's gas chamber and saw the convulsing body of 20-year-old Ronald Maddison thrashing around on the floor, spewing substances from his mouth.
Thornhill's eyewitness testimony will form a key plank of the reopened inquest into Maddison's death, which is due to be heard in the next few weeks.
Maddison, an RAF engineer from County Durham, had been used as a human guinea pig by MoD scientists experimenting on the lethal nerve gas sarin. Like hundreds of others from the armed forces, Maddison had volunteered for the trials, believing he was going to Porton Down to take part in some 'mild' experiments to find a cure for the common cold. Instead, by dropping sarin onto Maddison's skin, they used him to help determine the dosage of the lethal nerve agents.
Thornhill's accounts of the agonising last hours of Maddison's life shines a light into the murky past of this secretive establishment and the shocking experiments carried out on volunteers. Hundreds are suspected of dying prematurely or going on to develop illnesses such as cancer, motor neurone disease and Parkinson's. Despite the grief and fury of survivors and their families, over the decades successive Governments have sought to bury the scandal. But Thornhill's testimony could change all that.
'I had never seen anyone die before and what that lad went through was absolutely horrific... it was awful,' he said. 'It was like he was being electrocuted, his whole body was convulsing. I have seen somebody suffer an epileptic fit, but you have never seen anything like what happened to that lad... the skin was vibrating and there was all this terrible stuff coming out of his mouth... it looked like frogspawn or tapioca.'
Thornhill recalls a number of scientists standing around Maddison. 'You could see the panic in their eyes - one guy looked as if he was trying to hold his head down. There were four of us who picked him off the floor and put him in the back of the ambulance. He was still having these violent convulsions and we drove him to the medical unit at Porton.'
By the time he reached the unit, it had been cleared of other casualties and there were men in white coats standing around a bed.
Thornhill was told to carry Maddison over and it was then that the young ambulance driver saw a second image that would haunt him for decades.
'I saw his leg rise up from the bed and I saw his skin begin turning blue. It started from the ankle and started spreading up his leg. It was like watching somebody pouring a blue liquid into a glass, it just began filling up. I was standing by the bed gawping. It was like watching something from outer space and then one of the doctors produced the biggest needle I had ever seen. It was the size of a bicycle pump and went down onto the lad's body. The sister saw me gawping and told me to get out.'