Emmanuel Fisher (Sept. 25, 1921—July 22, 2001) was a British composer and conductor who was probably best known as the leader of the London Jewish Male Choir. But as a young army private during World War II, Fisher served in the British medical units that helped liberate the Bergen-Belsen concentration camp.

He did not know about Hitler’s “Final Solution” until he arrived at Belsen in the spring of 1945. “It was so horrendous that I thought in years to come I’d think that I’d exaggerated it, unless I kept a diary,” he told The Independent in June 1998.

“The whole thing was just like a bad dream,” he wrote in his diary. “I almost pinched myself to make sure that I was awake. … It was too unbelievable to believe. I was stunned.”

Aged 24, he was nurse, mother, and father to 150 to 200 patients. Within eight days, 6,000 patients were brought to the unit for treatment in army barracks outside the camp.

Tens of thousands died from disease, neglect and starvation. Among the victims: diarist Anne Frank.

Fisher’s diary is now archived in the Imperial War Museum. Watch his dramatic story in a videotaped interview conducted by the USC SHOAH Foundation: