Dehumanising people can lead to unimaginable horrors, a Holocaust survivor has warned.

This year, because of the pandemic, Islington Council hosted its Holocaust Remembrance Day online on the anniversary of the liberation of Auschwitz death camp.

The theme this year is ‘One Day’ – signifying how in just one day people’s lives can change irrevocably.

People across the borough and beyond were joined by the World Harmony Orchestra. Musicians performed work by composers considered “degenerate” and banned by the Nazi regime.

They played haunting pieces by Hanns Eisler and Kurt Weil about exile, with a theme of the “suffering, anxiety and loss” experienced by millions caught up in the horror of Holocaust.

Survivor Harry Olmer shared the horrific experiences of his Jewish family from a town in Poland.

Born Chaim Olmer in 1927, the retired dentist spoke movingly about life as the Nazis intensified their persecution of the Jews.

His home town was close to the German border.

He said: “In Poland, before the war, we heard propaganda from the Germans into our town through loudspeakers. You could hear the ravings from Hitler about the Jews and antisemitism was very severe.”

After the invasion of Poland it became much worse.

Olmer, who is now 94, described the murders he witnessed when just a boy. As the Nazis rounded up Jews to send them to labour camps, he recalled waiting in a square.

“Opposite us was an older man and his wife. They had no children, his wife was blind, and as they were going back the German soldier shot his wife there and then."

He described how men were taken away by the Nazis.

“As we were driving past the forest we could hear shooting going on. We knew what was happening. They were shooting men we had seen taken away earlier.

“One woman became hysterical, and started crying. The Germans stopped the truck and shot her.”

He was sent to do dangerous work making shells and mines in factories and at a quarry.

Life in the camp was horrific and people suffered from bed bugs and had “terrible food, cabbage and lumpy bread with the flour mixed with sawdust”.

He described how one night in the camp when he “just couldn’t bear it any longer”, he risked his life by turning on the light in the shower blocks. He thought the guards who had fierce dogs with them would kill him but they held back.

He was sent to Buchenwald concentration camp and eventually to Theresienstadt extermination camp, where he was liberated in May 1945.

“Everybody ran out,” he recalled, but he could not celebrate as he had been suffering from typhus.

“I was very, very ill. I don’t remember anything that happened to me for six to eight weeks. I was lying there, I couldn’t talk. My body was in spasms.”

In August 1945, he came to Windermere with other Jewish orphans who suffered so terribly in the Holocaust.

“And life started again, like a human being should live.”

Council leader Kaya Comer-Schwartz’s grandfather Paul Schwartz survived Dachau concentration camp, and her great-grandfather was murdered en route to Auschwitz concentration camp .

She said: “It is so important that we remember them and also learn how small acts of hatred can lead to the most horrific atrocities.”

The day remembers those killed in other genocides, including victims of slavery and those who died in Cambodia, Rwanda and elsewhere.

Islington South and Finsbury MP Emily Thornberry said: “The propaganda, they break down people to ‘other’, the lie that others are different to you.

“It can move very quickly to hate, to dehumanisation. You can shoot people while eating an apple and throw away the core.

“We have to remember how important it is that we always hold on to the fact that we are the same. There is no ‘other’."

“The other thing to learn from Harry is just how strong we can be, the strength of the human spirit and what we can achieve if we stick together," Ms Thornberry added.

Islington North MP Jeremy Corbyn said a key question was how civilised people became “such monsters under the Nazis by the demonization of the Jewish people, by the oppression of them and that eventually that antisemitism led to the Holocaust and the death camps”.

“It is all about education and people become dehumanised,” he added. “The lesson has to be never forget, the lesson has to be do not tolerate racism in any form, the lesson has to be that we take action on human rights.”

The online gathering heard pledges from pupils from Elizabeth Garrett Anderson School who learnt about the Holocaust and how to combat racism.