An intense search for the remaining crew of a missing Irish Coast Guard helicopter off the west of Ireland is resuming after being wound down overnight.
Hopes have faded for the survival of anyone on the Sikorsky S92 which lost radio contact without any warning at around 12.45am on Tuesday morning.
Captain Dara Fitzpatrick, 45, was pulled from the Atlantic off the Co Mayo coast - around six miles (10km) west of Blacksod - deemed critically-ill, but later confirmed dead.
She was the mother of a three-year-old son.
The other three crew, who have yet to be found, are chief pilot Mark Duffy from Dundalk, Co Louth, as well as Ciaran Smith and Paul Ormsby, both winchmen from north Co Dublin.
The Dublin-based helicopter crew was providing cover for another Coast Guard helicopter involved in an early-morning evacuation of a crewman needing urgent medical attention on a UK-registered trawler, approximately 150 miles (240km) west of Eagle Island in Co Mayo.
It had flown directly to the scene from the Irish capital, travelled around 10 miles (16km) out to sea, then turned back towards land to refuel.
There was no indication of any danger moments before it vanished, with the crew’s final transmission: “Shortly landing at Blacksod.”
Visibility was described as not good at the time.
When the helicopter failed to arrive, a Mayday signal went out and Coast Guard helicopters from Sligo and Shannon along with the Air Corps maritime patrol aircraft Casa were tasked to the scene.
They were joined by lifeboats from Ballyglass and Achill, the Naval Service’s LE Roisin ship and five local fishing vessels.
Officials from the Air Accident Investigation Unit are also at the scene carrying out a full investigation.
Jurgen Whyte, chief aeronautical officer with the unit, signalled the helicopter’s black box could be crucial to learning what went wrong.