A memorial service will be held in Erris this evening to mark the second anniversary of the Rescue 116 Coast Guard Helicopter crash.
Four crew members lost their lives when the Sikorsky S-92 aircraft crashed into Blackrock Island, in the early hours of March 14, 2017.
The bodies of Captain Dara Fitzpatrick and Captain Mark Duffy were recovered in the days following the tragedy.
The remains of their colleagues, winch operator, Paul Ormsby and winch man, Ciarán Smith, remain lost at sea.
Relatives of the deceased will gather for an Anniversary Mass at St. Brendan's Church, Eachléim, this evening.
Two years on from the crash, investigations into the incident are continuing and there are ongoing efforts to implement a number of recommendations made after the incident.