A brother of stabbing victim David Sheridan spoke of his heartbreak at the moment his life-support machine was switched off.
Gerry Sheridan (52) said his brother's stab wounds were so severe he could not have survived.
David, a father-of-three known affectionately as 'Gummy,' died in the Mater Hospital yesterday after being stabbed several times in an attack at a Dublin city centre takeway the previous night.
"The guards rang me at 6am and told me to come to the hospital fast as it didn't look good. When I arrived he was covered in tubes," Gerry told the Herald.
"When he was stabbed in the back, the knife severed an artery. The doctor told me nothing more could be done and I agreed the machine be switched off."
Gerry said he understood a man had an argument with his brother on Sunday night in a takeaway on North Strand. The man returned shortly after and stabbed him several times.
"David had a very sad life. A brother and a sister took their own lives when he was young. He spent years as a child in the industrial school in Clonmel where he was sexually abused.
"That place changed him in a bad way and when he got out he got into robbing and doing drugs and ended up in prison. He became a heroin addict and an alcoholic.
"He got a quarter of a million euro in compensation for what happened him in Clonmel and he drank most of it, along with his friends. He was on methadone too."
Speaking at his home off Sherrard Street, he said: "I felt he was lost. I was looking after him recently until about a week-and-a-half ago when he left."
Anita Judge, mother of David's teenage son, told the Herald: "David was a very good man with a very big heart."
Speaking at her home in Finglas East, she said she had a six-year relationship with him with many happy memories.
"I'm very angry. David didn't deserve this after all he'd been through in his life," she said.
"It's wrong to take a life. He was a good dad to his son."
Gardai believe footage from CCTV cameras will help them identify the attacker, who fled on foot. The victim was well-known to gardai and had a series of criminal convictions.
He was given a two-year suspended sentence for robbery by Dublin circuit criminal court last January.
He also had previous convictions for damage to property and theft and threatening behaviour.
Mr Sheridan, who had an address at Charleville Mall in the inner city, had called into the takeaway at 10.30pm.
He became involved in an argument with another customer, who then left the premises.
The other man returned shortly afterwards and viciously attacked him with a knife.
A number of potential witnesses to the attack were interviewed by officers yesterday as detectives tried to establish a firm motive for the stabbing.
One officer said: "The attacker ran off after the verbal row and returned very quickly with the murder weapon.
"House-to-house inquiries are being carried out in the vicinity and should help to determine if the attacker lives nearby or explain how he had ready access to the knife," he added.
Last night gardai appealed to anybody with information about the stabbing or who was in the North Strand area between 10.15pm and 10.45pm on Sunday to contact the incident room at Mountjoy station, tel 01 666 8600, or the garda confidential line, 1800 666111.