1977 Washington, D.C., attack and hostage taking
The 1977 Hanafi Siege was a terrorist attack, hostage-taking, and standoff in Washington, D.C., lasting from March 9 to March 11, 1977. Three buildings (the District Building, B'nai B'rith headquarters, and Islamic Center of Washington) were seized by twelve Hanafi Movement gunmen, who took 149 hostages.
Source: Wikipedia — 1977 Washington, D.C., attack and hostage taking (CC BY-SA 4.0)