Post-mortem examinations are to be carried out on the bodies of two elderly brothers found dead in their home.
The men, both aged in their seventies and named locally as Dan and William McCarthy, were discovered in the house in the Bluebell area of west Dublin on Tuesday at about 5pm.
The brothers were both deaf and had been living in the area for most of their lives.
It is understood that Dan acted as the carer for the two of them.
Investigations are centring on whether he died first, with his brother William remaining in the house on the Millrose Estate unable to care for himself or to make contact with anyone to raise the alarm.
Gardai said the deaths were being treated as a tragic incident and foul play is not suspected.
It is understood a member of the public raised the alarm after the men were not seen for a number of days.
The bodies of the two men were removed from the house and post-mortem examinations are due to take place in the Dublin City Morgue in Marino to establish the cause and time of the deaths.
Gardai in Kilmainham are investigating.
Neighbours described the brothers as quiet men who kept to themselves.
A parish newsletter from Our Lady of the Wayside Church in Bluebell was delivered to the house each week and was one of the regular contacts the men had with the local community.
It is understood concerns for the brothers were first raised over the weekend, and attempts were made to force entry into the house late on Monday and into the early hours of Tuesday.
A ladder was used to get into the property which backs on to the Grand Canal.
One of the brothers had a car and one was also regularly seen using a bike and shopping locally.
Justin Moran, head of advocacy and communications with Age Action, said the deaths were a heartbreaking tragedy.
"It's a reminder to all of us that people can become isolated anywhere," he said.
"When we talk about social exclusion we tend to think of it more in rural areas, where someone is living well outside of town, but this tragedy in a busy Dublin community like Bluebell shows it can happen in our big cities."
Mr Moran urged people to inquire after their older or vulnerable neighbours.
"There's often a reluctance to do so. No one wants to be seen as interfering or nosy, but our experience is that it's always appreciated," he said.
The brothers had lived on the estate in Bluebell for more than two decades.
It is understood their home was occasionally targeted by youths throwing stones from the canal bank but otherwise they rarely came to the attention of residents.
Andy Connolly, a neighbour who is involved in the local residents' association, said: "It's a terribly sad situation. There is deep shock locally.
"The problems that they had communicating, maybe they just didn't fall into the neighbourhood like everyone else. Maybe both sides saw it as a difficulty.
"But you'd wonder whether the whole thing should be brought into question about what kind of support or help had they.
"There are a number of elderly people in the estate and the attention that they get from neighbours is second to none, but in this case there was a sense of isolation."
Sean Moynihan, chief executive of the Alone charity, which supports older people in their homes, sa id: "We are asking all older people not to be afraid to ask for help if they are feeling isolated or lonely. It is very easy to become cut off from your local community."
He added: "I don't think that people are aware just how devastating loneliness can be for your general health.
"Not only can loneliness lead to depression, but it is also a predictor for dementia, cardiovascular disease and decreased immune system response. Loneliness is twice as dangerous to the health of an older person as obesity, and is as damaging as smoking 15 cigarettes a day."