A man died after medical technology, including sleep apnoea equipment, stopped working during Storm Éowyn, the Dáil has been told.
Sinn Féin TD for Mayo Rose Conway-Walsh said she was informed of the death by a constituent.
In a separate incident, Kacper Dudek, 20, was killed when a tree fell on his car in Co Donegal on the morning of the storm.
Ms Conway-Walsh told the Dáil: "I was on Midwest Radio this morning, and I said I have been frightened all week that something was going to happen, that somebody was going to die as a result of this in Mayo.
"I do want to extend my condolences to the man's family in Donegal that lost his life, but very shortly after (the radio appearance), somebody from our own constituency rang me to describe to me how the equipment that his father was using couldn't be used - the mattress, the sleep apnoea, the several other pieces of equipment - they couldn't be (used).
"When he went then to take his father to the doctor, he died in front of him.
"And that is the tragedy of it, and that is how urgent this is."
Storm Éowyn is now the 'precedent' - Calleary
The Department of Social Protection's focus continues to be on those without power, Minister Dara Calleary said during a debate on the storm.
Speaking in the Dáil he added that "whilst Éowyn was unprecedented, it is now the precedent".
The Fianna Fáil TD said people would be helped with the cost of food, and some were being assisted with accommodation, where required.
3,818 payments totalling €727,792 had been paid out to those without power by his department.
Mr Calleary said a full phone and email service had been provided throughout the bank holiday weekend by the department.
Minister for Transport Darragh O'Brien acknowledged "that as of this morning, 18,000 customers still remain without power".
He said the Government's priority is to assist "in the restoration of power to all as quickly and as safely as possible."
Mr O'Brien said that "specific learnings" for the electricity sector have already emerged.
Meanwhile, Minister for Housing and Local Government James Browne described Storm Éowyn as one of the most dangerous and destructive storms in history.
He said preparations were underway from 20 January - with various stakeholders working together, including the Department of Housing and the Environment and the ESB.
"Two full NECG [National Emergency Coordination Group] meetings took place before Storm Éowyn," he said.
He said a press briefing was also held to prepare the public for the damage and destruction.
Mr Browne said these messages were heard by the public, as evidenced by reduced traffic on the day of the storm.
He said the exceptional scale of the damage, brought extreme hardship for households and that a systematic review would be carried out once the response to the events had concluded.
Response '12 days too late' - SF
However, Sinn Féin's Claire Kerrane said the Government was "12 days too late" and that the vast majority of homes are now reconnected.
She said the people of Roscommon and Galway were feeling anger and pain and were let down by the Government.
People did not have enough money to pay for alternative accommodation upfront, said Ms Kerrane.
She said the ESB needed an urgent plan to protect their power lines from trees - saying forestry was in a mess.
Her party colleagues Mairéad Farrell and Ms Conway Walsh, who both also represent constituencies in Connacht, highlight the challenges the storm raised for their constituents.
Ms Farrell said that a supposedly "once in a lifetime" event is happening to people in the west as a "regular occurrence".
She said one constituent was left without power for four days during Storm Darragh, and their father got pneumonia and then died.
"This is life or death for these people," she said. "That's a massive job of work".
Communication has been very poor, she added, noting that as the Dáil had not been sitting, TDs did not know "what was going on".
Ms Conway Walsh said there was real real hardship being suffered by people and said the response was not good enough.
She added that she did not think the Dáil would have remained in recess if the storm affected Dublin in the way Mayo was affected.
She added that she could not understand why the army had not been brought in.
ESB left to do heavy lifting - Whitmore
Social Democrats TD Jennifer Whitmore said there was no "whole of Government approach".
The ESB was left to do all the heavy lifting, she said, and asked if the HSE could have done more.
She said it was unfortunate that Minister for Agriculture Martin Heydon was not in the Dáil, as she said the horticulture sector was hit badly and needs a support scheme.
Mr Heydon acknowledged the "significant damage" caused in the sector.
Polytunnels have been destroyed, he noted.
His colleague, Micheal Healy-Rae, will meet with growers next Tuesday to hear their concerns.
Fianna Fáil TD Cathal Crowe said that the Government will have to "step up" to compensate the sector.
Having studied wind gust speeds, he thinks Storm Éowyn should be reclassified retrospectively as a hurricane.
The Social Democrats deputy leader has also said the political response has not matched the impressive work of emergency teams.
"The State's inadequate response to Storm Eowyn has led to understandable anger," Cian O'Callaghan said.
For some people "the incorrect information on restoration dates really added to their sense of frustration", he added.
Wakes being held by candlelight over outages - Bacik
Earlier, Labour leader Ivana Bacik said people have been forced to hold wakes for dead relatives in candlelight due to the ongoing fallout from the storm.
It is unacceptable that 18,000 homes, farms and businesses are still without power and some will not have their electricity restored until the weekend, she said.
People cannot afford the financial cost of repairs which the ESB is intending to pass on to customers, she told the Dáil.
Ms Bacik asked the Taoiseach what additional supports the Government will now provide to people worst affected by the storm.
Micheál Martin responded saying it was the worst storm in a century and he has already advanced the plan to upgrade the electricity grid to make it more resilient.
He said it was not good enough that Uisce Éireann did not have generators at all locations, adding this will not happen again.
The Taoiseach predicted that the number of storms and their severity will increase in the years ahead and the country will have to build up its resilience.
Additional reporting: Juliette Gash & Mícheál Lehane
