 This incident sparked the Irish Civil War as fighting broke out around the country between pro and anti-treaty factions.On 8 December 1922, along with three other republicans Liam Mellows, Richard Barrett and Joe McKelvey captured with the fall of the Four Courts, Rory O'Connor was executed by firing squad in reprisal for the anti-treaty IRA's killing of Free State TD Sean Hales.The execution order was signed by Kevin O'Higgins.