One mother's heartbreaking acts of selflessness amid the horror of Aushwitz stand as a beacon for the human spirit.
Vilma Grunwald was sent to the death camp with her husband, Kurt, and two sons, Frank and John.
Initially, they had been persecuted in their home in Prague, Czechoslovakia.
The boys were banned from school and the whole family were ordered to wear the yellow Star of David badges to identify them as Jewish.
But then, on December 15, 1943, the whole family were deported to Auschwitz.
Separated by sex, Frank and John lived with their father, while their mother lived with the other woman.
Frank even managed to work as a errand boy to buy extra clothes and necessities for his family but then, on July 6, 1944, the German's changed the rules.
John was 16 and his younger brother, Frank, was just 12.
Nazis deemed the 'family camps' should no longer exist and Kurt was set to work in the death camp with the other fit men and just days later Frank's mother and brother would be dead.
On July 11, John, who was disabled and walked with a limp, was sent to the gas chamber.
Unwilling the let her eldest son die surrounded by strangers, Vilma made the selfless decision to stay with him.
But before she was murdered in the gas chamber, her final thoughts were for the husband and son she was leaving behind.
Vilma scribbled them a heartbreaking note, which she handed to a guard she deemed to have compassion, and begged him to make sure her remaining family received the letter.
Frank wrote on Sky News: "My mother, who was always a good judge of character, had picked the right person."
She and John then became two of the millions murdered by the Nazis during World War Two.
Meanwhile, just a few months later, in October 1944, Kurt was transfered to Mauthausen concentration camp in Austria, forcing him to leave his little boy behind.
Frank himself as then forced on a death marked in January, 1945, as the Soviet forces made their way to liberate Auschwitz.
Just a child, he had to walk through the snow and past the bodies of those too weak to keep up who had been shot dead by the guards.
Starving and struggling, Frank reached Gleitwitz and was finally freed in Gunskirchen in May 1945 by US troops.
Frank was reunited with his father a few weeks later and the pair returned to their home city of Prague, where Kurt remarried and his son finished school.
It was then that he first learned about his mother's letter.
Frank said: "My father told me it was a goodbye, a loving goodbye to him, and that my mother had wished him a good life."
At just 12, Frank was too young to feel he wanted to read his mother's final words.
But then, when Czechoslovakia became a Communist state, the father and son fled and landed in America in 1951.
Kurt worked as a doctor while Frank continued his studies.
At just 12, Frank was too young to feel he wanted to read his mother's final words and it wasn't until his father died in 1967, Frank found his mother's poignant letter, penned inhe moments before her death.
Here are her heartbreaking words:
"You, my only one, dearest, in isolation we are waiting for darkness.
"We considered the possibility of hiding but decided not to do it since we felt it would be hopeless.
"The famous trucks are already here and we are waiting for it to begin. I am completely calm.
"We did what we could.
"Star healthy and remember my words that time will heal - if not completely then at least partially.
"Take care of the little golden boy and don't spoil him too much with your love.
"Both of you - stay health, my dear ones. I will be thinking of you and Misa. Have a fabulous life, we must board the trucks.
"Into eternity, Vilma."
Frank was astounded at how positive his mother was in the face of her death and how she lacked any hatred towards the Nazis.
For years, Frank kept the letter locked up in a cupboard in his home in Indianapolis, never showing it to anyone but re-reading it every few moths.
Finally, he felt able to share its contents with his wife, Barbara, and their two sons.
But Frank realised keeping the letter for himself was doing neither him, nor the memories of those who died, any good and he made copies and gave the original to the US Holocause Memorial Museum in Washington.
Frank said: "I've had so many emails and letters both from people I know and people I don't.
"I remember telling my wife that I was so concerned that, when I am not around, my mtoher will be forgotten.
"Now that they letter is on exhibit at the museum, she will not be."
