On August 4, 1944, the Secret Annex was invaded by German police after receiving an anonymous tip. The group of eight people were detained and held for the night in nearby cells before being taken to the transit camp Westerbork the following day.
On September 3, 1944, Anne and her sister Margot were transferred to the Auschwitz-Birkenau extermination camp in German-occupied Poland. Their parents, Otto and Edith Frank, remained at Westerbork along with the other three people that were arrested from the Secret Annex.
At Auschwitz-Birkenau, Anne and Margot had to endure harsh living conditions, disease, and malnutrition. In late October or early November 1944, they were moved to the Bergen-Belsen concentration camp in Germany.
In February 1945, typhus broke out in the overcrowded and unhygienic conditions at Bergen-Belsen. Anne's sister, Margot, passed away from the illness in March. Anne died of typhus a few weeks later, around the end of March or early April 1945, just a few weeks before the British liberated Bergen-Belsen on April 15, 1945.
Otto Frank was the sole survivor of the Frank family. After learning about the deaths of Anne and Margot, he dedicated himself to preserving their memory and sharing Anne's diary with the world.