Another man has died in a double tragedy after being overcome by fumes while working in a sewer.
Stephen Harris, 34, of Monasterboice Road in Crumlin, Dublin, lost his fight for life in Beaumont Hospital at 9am today.
He was caught up in the same suspected methane gas incident which claimed the life of his brother, Alan Harris, a father of two, on Wednesday.
The pair had been inspecting underground pipes on a housing estate in the Portmarnock area of north Dublin.
Alan Harris, in his 40s, was the owner of DrainTech, a company specialising in drainage clearance and pipe and sewer unblocking in the Dublin region for about 20 years.
The accident happened on the Drumnigh Woods estate in Portmarnock.
The brothers were beginning to assess work on pipes under the road, some of which were reported to be 20ft (6m) below the surface.
Stephen Harris, who was knocked unconscious by the noxious gases, was rescued by fire crews but lost his fight for life in hospital.
His family requested that their privacy be respected during their grief.
Investigations by the Garda and the Health and Safety Authority are continuing.
"The scene of the incident is still preserved for investigation purposes," said a Garda spokesman.
Both the deceased men are cousins of Republic of Ireland striker Robbie Keane.
Keane did not speak about the tragedy as he trained with the Republic squad earlier this week in Malahide, a few miles from the scene.
Questions centre on whether the men were overcome by methane gas in a confined space as they began initial assessments of the work to be done on the sewers.
Inquiries will also look into what breathing apparatus was available to the men.
Keane, 34, is expected to play a part in Saturday's Euro 2016 battle with Scotland in Dublin.
The LA Galaxy star took to Facebook last night to pay tribute to cousin Alan and say that his family were praying for Stephen.
"As you can imagine it's been a very difficult time for our family may Alan RIP and we continue to pray for Stephen thanks everyone for your kind messages and support," he posted.
A number of people posted messages of sympathy to the footballer.
Alan's grieving widow Tracy Glynn Harris also posted on the social media website that she had lost her "best friend and soulmate".
"My heart has been shattered into a million places yet again," she wrote. "Thank you all for the kind words."
Ms Harris also implored people to say prayers for Stephen, who she said was fighting for his life after trying to save his brother.