Easter Rising in putting the rising off for only a day, although it greatly reduced the number of Volunteers who turned out. British Naval Intelligence had been aware of the arms shipment, Casement's return, and the Easter date for the rising through radio messages between Germany and its embassy in the United States that were intercepted by the Royal Navy and deciphered in Room 40 of the Admiralty. The information was passed to the Under-Secretary for Ireland, Sir Matthew Nathan, on 17 April, but without revealing its source, and Nathan was doubtful about its accuracy. When news reached Dublin of the capture
Centenary of the Easter Rising Dublin Society and met relatives of the dead, 4,000 of whom attended. President Higgins later attended a 1916 commemoration concert at Liberty Hall Theatre. On the same day, Acting Taoiseach Enda Kenny and Acting Arts Minister Heather Humphreys opened a permanent visitor centre at the General Post Office, scene of rebel occupation in 1916. Also attending was former Taoiseach Liam Cosgrave, whose father W. T. Cosgrave reopened the building in 1929 after it was put back together. A commemorative service was held at the Unitarian Church on St Stephen's Green, with the names of all Dublin fatalities read aloud. The