Crime boss Eamon Dunne was abandoned by his close associates as a gangland hit-man fired six bullets into his head and back in a Dublin pub at the weekend.
Dunne had been partying with about 40 people in Cabra when he was singled out and killed.
But they all fled the scene immediately after the killer and his accomplice left the pub without going to his aid, the Irish Independent reports.
"Nobody even bothered to check whether he was still alive," one eyewitness told the paper. "All of those who had been regularly seen by his side during the past few years ran away."
The gunman appeared to know where Dunne was sitting when he entered the Fassaugh House pub, at 10 p.m. last Friday.
Beforehand, four men pulled up outside the pub in a silver-colored saloon car. The driver stayed in the car as a second stood outside the entrance to the pub.
The gunman, who wore dark clothing with a hoodie pulled down over his face, walked into the middle of the group of partygoers before firing his automatic pistol. His accomplice then fired a warning shot into the air.
Dunne had been responsible for a reign of terror in Dublin's gangland since he took charge of the remnants of the drug trafficking and armed robbery gang after the murder of its former leader, Martin "Marlo" Hyland, in a house in Finglas in December 2006.
Gardai said they had told Dunne several times that they had intelligence that his life was in danger from those seeking revenge for killings he had ordered.