The tragedy unfolded at a three-bedroomed terraced house in the St Colman’s Park estate in Macroom in Co Cork yesterday.
Inside were Nóirín McAuliffe, in her late 50s, her son, 26-year-old Kenny Relihan, and family friend Noel O’Mahony from nearby Clondrohid, who was in his early 60s.
Gardaí are investigating how the fire started, but one theory is that a chip pan or fat fryer may have sparked the blaze.
The alarm was raised by a next-door neighbour shortly before 4am with units of the fire brigade from Macroom and Ballincollig at the scene within minutes.
Local people had been calling on those inside to get through a window. Ms McAuliffe jumped from the upstairs bedroom window, and yesterday was being treated in the intensive care unit at Cork University Hospital.
Her son had been out at a local nightclub and both he and Mr O’Mahony, a father of three, failed to get out of the property, despite heroic attempts by some neighbours to get them out.
Tim Coleman, 21, who lives across the road from the house, made a number of attempts to get to the men. He told RTÉ Radio that he was treated for cuts and bruises after his efforts.
“I tried going in, I got up one, two steps, but the smoke was too much,” he said.
Mr Coleman said he heard Ms McAuliffe screaming and told her she had to jump to get out of the house.
“She jumped and I went back in again,” he said. “I only got to the second step again.
“I couldn’t do any more.”
Tim Coleman, who saved a woman from this morning's tragic house fire in Macroom, describes the harrowing eventhttps://t.co/aiVCtHKFLm— RTÉ News (@rtenews) May 2, 2016
Former local councillor Martin Coughlan, another neighbour, said rescue efforts also included a ladder being propped next to the upstairs window.
Ms McAuliffe has three other children from an earlier marriage and it is understood two of her daughters live locally. The bodies of Mr Relihan and Mr O’Mahony were taken to Cork City for autopsies.
Mr Coughlan described the tragedy as “awful” in a “well-established” area. “This is tough, very tough,” he added.