Following a Northern Ireland Civil Rights Association march on 30 January 1972 in the events now known as Bloody Sunday , in which Friel participated , the British 1st Battalion Parachute Regiment opened fire on the protesters which resulted in thirteen murders . An early form of the play , having been started approximately ten months prior to Bloody Sunday , was modified following the events of the day to entail certain links to the events
Bloody Sunday
Bloody Sunday (1972)
The Freedom of the City