We drove in and saw a sight that shocked us as nothing, even the sights of war, had ever shown us before. There was a stench of death everywhere. We were there for about two weeks filming and I thought as time went by it might leave me. I wanted to forget. But it never does leave you." These are the words of Sgt Mike Lewis, army cameraman at Belsen, speaking decades after the liberation of the concentration camps.
Like all of the cameramen, editors and producers of the film shot at liberation, the memory of what was encountered has haunted Sgt Lewis for the rest of his life and the psychological wounds of bearing witness were most noticeable through silence.
The Army Film and Photographic Unit, accompanying the troops that entered the camps 70 years ago, had been totally unprepared for what they were about to encounter, but, on being confronted with the unimaginable, picked up their cameras and filmed. Once there, they were sent to gather evidence at the instruction of Sidney Bernstein, then chief of the Allied force's Psychological Warfare Department. The intended use of their film was as part of a de-Nazification programme to show to the Germans.
Bernstein's instructions were to film everything: his intention was to create a film that would provide evidence for all mankind. He would shape this film with a team that included Alfred Hitchcock and future cabinet Minister Richard Crossman. It was not completed in Bernstein's lifetime and I have been involved in the film Night Will Fall, which tells the story behind Bernstein's project, why it was stopped and of the Imperial War Museum's extraordinary restoration and completion of that film.
We've been incredibly privileged to have testimony from liberators, cameramen, editors and some of the survivors who were filmed.
Much of the footage assembled by Bernstein's team is familiar to us, but it's only when you see it in its proper context, together with the brilliant words in Crossman's script that the true power and pain of the images can be felt.
Traditionally, combat cameramen had shied away from representing scenes of people who had been brutalised or killed but at Belsen they had to show the extent of the barbarity of the Nazis. As a consequence, the footage is unflinching: dead and wounded bodies, burial pits and industrial signs to emphasise culpability.
Nonetheless, the cameramen were aware of their limitations, feeling that all they could manage was an approximation of the atrocities that they had encountered.
It's in their dope sheets, or logs, that a sense of the inadequacy of the camera to capture all they were experiencing can be felt. There are entries that reveal their awareness of the need to gather evidence. One entry reads: "Showerhead - note no oxidisation." Other entries record the limitations of the camera to capture the stench and sounds of the camps.
How did they manage to work through this? For some, the only response to such horror was a form of dissociation. "You lost contact with reality. You could never associate what you were seeing with your own life… if we had become too involved I think you would probably have gone mad,'' said Sgt William Lawrie, army cameraman.
During the course of making Night Will Fall as a producer and psychotherapist, I have been struck by how much those people who bore witness to that atrocity had to carry and how difficult it was to share that experience with others.
One of the key messages of Bernstein's film is that we must not look away, as the local townspeople living close to the camps did in the 1940s. As Richard Crossman wrote in his original script: "If we don't learn the lessons these pictures teach, night will fall, but by God's grace, we who live will learn."
'Night Will Fall' is on Saturday, Channel 4 at 9pm.
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