In August 1969, intense rioting broke out in Northern Ireland, the most violent being in Belfast. In the Northern Ireland riots of August 1969, Cahill, along with Billy McKee, tried to defend the Catholic Clonard area from attack, but was unable to prevent Bombay Street being burned by Ulster Protestant rioters. When he subsequently tried to organise the defence of the Ballymurphy area, he was initially chased away by its Catholic residents. The 1969 Northern Ireland riots displaced 1,800 families from their homes. It was a humiliation for the IRA and made evident that they could not protect their people. The slogan 'IRA: I Ran Away' was painted on walls all over Belfast. The riots were said to be the beginning of "the Troubles" in Ireland.