The Coast Guard has confirmed that the crew member rescued this morning off the coast of Mayo has died.
Captain Dara Fitzpatrick was one of four people on board. The other three occupants of the helicopter which went missing at 1am this morning in Blacksod, Co. Mayo have yet to be located.
According to RTE, Captain Fitzpatrick had over 20 years experience and was involved in several water safety campaigns.
Gerard O'Flynn, the search and rescue operations manager with the Irish Coast Guard, said that the news of the fatality was a hammer blow to the emergency services.