Who knew about the holocaust while it was happening?

During the Holocaust, various individuals and groups were aware of the atrocities occurring in Nazi-occupied Europe. Reports from resistance movements, refugees, and underground networks reached governments and organizations, including the Allied powers, who received intelligence about the mass exterminations. Additionally, some individuals in Germany and occupied territories, including local populations and church leaders, were aware of the actions against the Jews and other targeted groups, though responses varied widely. However, the full extent of the Holocaust was not fully understood until after World War II ended.