Two men , Séamas Cusack and Desmond Beattie , were shot dead in separate incidents in the early morning and afternoon of 8 July 1971 . They were the first people to be killed by the British Army in Derry . In both cases the British Army claimed that the men were attacking them with guns or bombs , while eyewitnesses insisted that both were unarmed . The Social Democratic and Labour Party ( SDLP ) , the newly formed party of which John Hume and Ivan Cooper were leading members , withdrew from Stormont in protest , but among residents there was a perception that moderate policies had failed . The result was a surge of support for the IRA . The Provisionals held a meeting the following Sunday at which they called on people to " join the IRA " . Following the meeting , people queued up to join , and there was large @-@ scale rioting . The British Army post at Bligh 's Lane came under sustained attack , and troops there and around the city came under fire from the IRA .