Her neighbourhood was bombed by the allies, the Jews around the corner were being sent to Auschwitz and the Red Army had launched its final assault on Berlin. But Brigitte Eicke, a teenaged German, was unconcerned. She was far more interested in going to the cinema, dancing to gramophone records and trying to cope with a "disastrous" perm.

The 15-year-old Berlin schoolgirl, nicknamed "Gitti", started keeping a diary in December 1942, when the German capital was being bombed nightly and the Nazi Holocaust was killing thousands. As a trainee secretary, she recorded her daily experiences to improve her stenography skills.

Now, some 70 years on, her diary has been published for the first time in Germany and is being hailed as remarkable documentary evidence of how millions of Germans relied on collective indifference to endure the horrors of war and ignore the brutality of the Nazi rule.

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Entitled Backfisch im Bombenkrieg (teenaged girl in bombing war), Eicke's diary is an often banal account of everyday life. She started writing it just months before Anne Frank began her diary, but the contents could hardly be more different.

"Gitti is merely a cog in the wheels that kept Nazi Germany turning," is how Der Spiegel magazine described the author last week. "She is a young woman skilled in the art of blotting out ugliness, willing to believe what she's told and, ultimately, one of the lucky ones," it added.

Here is Gitti's entry for 1 February 1944: "The school had been bombed when we arrived this morning. Waltraud, Melitta and I went back to Gisela's and danced to gramophone records." In another raid on her Berlin neighbourhood in March 1943, two people are killed, 34 are injured and more than 1,000 are made homeless. Gitti writes: "It took place in the middle of the night, horrible, I was half asleep".

In November 1944, Hitler is trying to cripple the advances made after the D-Day landings by planning an offensive in the Ardennes, but Gitti – by now a member of the Nazi Party – is more concerned about her hairdo. She writes that she has just been given a "disastrous" perm by her hairdresser and is worried about going to work "looking a fright".

Then on 2 March 1945, while Hitler's troops are trying to halt the Red Army's advance just 60 miles east of Berlin, Gitti, now 18, goes to the cinema. She writes: "Margot and I went to the Admiralspalast cinema to see Meine Herren Söhne. It was such a lovely film, but there was a power cut in the middle. How annoying!"

The humdrum tone is all the more disquieting when it comes to the steady disappearance of Berlin's Jews – an issue that receives only one mention in the entire diary. On 27 February 1943, she ends a trivia-packed account about how she and her friend Waltraud go to the opera and get chatted up by soldiers on the way home with the entry: "Jews all over town being taken away, including the tailor across the road."

Brigitte Eicke is now 86. She still lives in east Berlin's Prenzlauerberg district, where she lived during the war. Just around the corner from where she worked as a secretary, there was a "collection centre" for Jews who were being sent to the Auschwitz death camp.

In a recent interview to coincide with the publication of her diary, she said: "My son always said to me: how could you be so oblivious? But I never saw a thing." She added: "There were some Jewish girls in my first class photograph taken in 1933 but, by the time the next one was taken, they were all gone. When I asked my mother about them, she said they had moved to Palestine."

Decades would pass before she grasped the enormity of the Nazis' crimes. "It was only when I visited Buchenwald in 1970 that I saw photographs of the camps. It took me years to realise what had gone on," she said.

Unlike thousands of young German women, Brigitte Eicke appears to have escaped being raped by Red Army troops when they took Berlin. But she lost her father and an uncle on the eastern front. Some German commentators have suggested that her naive and apolitical account of her experiences was an unconscious survival attempt.

"We just muddled through, we had no choice," is how she describes it.