The worst act of Sinn Fein arson: The Burning of the Customs House at Dublin on 24 May 1921. The Burning of the Custom House in Dublin took place on 25 May 1921, during the Irish War of Independence. The Custom House was the centre of Local Government in the British administration in Ireland. It was occupied and then burnt in an operation by the Irish Republican Army (IRA), involving over 100 volunteers. The action was a propaganda coup for the forces of the Irish Republic but was a military disaster for the IRA in the Irish capital. Five of its volunteers were killed (along with three civilians) and over 80 captured. The Customs House, designed by architect James Gandon was built in 1785 with further additions in 1794 and 1811.