Post mortem examinations are to be carried out on the bodies of two men who died during an Ironman event in Co Cork.
Canadian national Ivan Chittenden (64) was believed to be from Toronto and on holidays in Ireland with family members, while Meath native Brendan Wall (44) had been living in England for a number of years.
They died in the swimming section of the race in Youghal on Sunday morning when both men suffered separate medical emergencies.
Organisers said safety personnel provided immediate medical attention when they recognised the athletes were in need of assistance.
"We share our greatest sympathies with the families and friends of the athletes and will continue to offer them our support as they go through this very difficult time," they said in a statement.
Irish Independent Southern Correspondent Ralph Riegel told Newstalk Breakfast the tragedies happened early on in the competition.
"It really has shocked I think not just the town of Youghal, but endurance sports fans all over Europe," he said.
"We know that the two fatalities happened quite early in the morning.
"The events began around 8am and one man got into difficulty in the water [and] he was very quickly taken from the water.
"But despite the very best efforts of doctors and paramedics on the shoreside, he was pronounced dead in Youghal."
Ralph said the swimming portion of the race had already been reduced.
"The swim element was 1.9 kilometres - that was shortened from a longer distance because of the lingering conditions from Storm Betty," he said.
"Anybody that might have seen some social media coverage of the event would see that there was quite large waves breaking on the shoreline.
"This second individual, similarly, it was realised he was in difficulty in the water.
"He was given emergency medical assistance... again he was brought to shore, and sadly despite the very best efforts of medical personnel he was pronounced dead at the scene."
'Should it have gone ahead?'
Ralph said questions are being asked about the competition itself.
"The remains of the two individuals were brought to Cork University Hospital," he said.
"The Office of the State Pathologist was notified, and we're expecting post mortem examinations to be conducted today.
"The finding of those post mortem examinations are going to be critical.
"At this stage it is believed that personal medical emergencies were a key factor in both deaths.
"If that's the case, it's obviously going to direct where the safety investigation goes.
"Certainly the two questions that are being raised locally is given the nature of the water conditions, should that part of the race have gone ahead?
"A number of swimmers had said they found the very first section of the swim quite challenging.
"The second element... is once it was known that there were fatalities involved, should the entire event have continued as it did?" he added.