1977 Hanafi Siege including B'nai B'rith headquarters

On March 9, 1977, members of the Hanafi Movement led by Hamaas Abdul Khaalis seized three Washington buildings, including the B'nai B'rith headquarters, taking hostages in a standoff that lasted roughly 39 hours. The siege resulted in negotiations mediated by religious leaders and the eventual peaceful surrender of the gunmen; three people had been killed in related earlier attacks that prompted the siege. The event drew national attention to religious and racial tensions and to security at civic institutions.